<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a01620-5151-75e7-b5eb-299428e3f04c,g:5b8dc30c-40be-4a36-8f3e-63fadf94a0ad-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.newtekone.com/role/Cover" xlink:type="simple" xlink:href="newt-20260930.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_01a01620-57c8-7d5c-a81d-e51453102d95" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentInformationTable_01a01620-57c8-7d5c-a81d-e51453102d95" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7d98-92f0-d63627b94a88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_01a01620-57c8-7d5c-a81d-e51453102d95" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7d98-92f0-d63627b94a88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7d98-92f0-d63627b94a88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7d98-92f0-d63627b94a88" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7d98-92f0-d63627b94a88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7d98-92f0-d63627b94a88" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommonStockParValue002PerShareMember_01a01620-57c8-7f37-9898-ab47ea65402b" xlink:href="newt-20260930.xsd#newt_CommonStockParValue002PerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_CommonStockParValue002PerShareMember_01a01620-57c8-7f37-9898-ab47ea65402b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2028NotesMember_01a01620-57c8-73b8-a02b-23da180885cc" xlink:href="newt-20260930.xsd#newt_A2028NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_A2028NotesMember_01a01620-57c8-73b8-a02b-23da180885cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a01620-57c8-7a13-944e-b4278b716918" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_A20298.50NotesMember_01a01620-57c8-7a13-944e-b4278b716918" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.625NotesMember_01a01620-57c8-7100-8a28-d950a7649a22" xlink:href="newt-20260930.xsd#newt_A20298.625NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_A20298.625NotesMember_01a01620-57c8-7100-8a28-d950a7649a22" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-57c8-7747-a4f4-a8182ff1a3b7" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_A20318.50NotesMember_01a01620-57c8-7747-a4f4-a8182ff1a3b7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SeriesBPreferredStockDepositarySharesMember_01a01620-57c8-7791-b7d1-2b96162d8aa5" xlink:href="newt-20260930.xsd#newt_SeriesBPreferredStockDepositarySharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-70f1-b5d6-1035472e1005" xlink:to="loc_newt_SeriesBPreferredStockDepositarySharesMember_01a01620-57c8-7791-b7d1-2b96162d8aa5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_01a01620-57c8-7815-9b06-833e5ec63a73" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentType_01a01620-57c8-7815-9b06-833e5ec63a73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_01a01620-57c8-7915-943a-c1f14ebbe459" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentQuarterlyReport_01a01620-57c8-7915-943a-c1f14ebbe459" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_01a01620-57c8-7a8b-981b-b17a9b612ac7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentPeriodEndDate_01a01620-57c8-7a8b-981b-b17a9b612ac7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_01a01620-57c8-797e-ad80-ab7575863f8d" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentTransitionReport_01a01620-57c8-797e-ad80-ab7575863f8d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_01a01620-57c8-7a47-a578-c795e7912bdd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityFileNumber_01a01620-57c8-7a47-a578-c795e7912bdd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_01a01620-57c8-7b6d-9c2d-d48abe34569f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityRegistrantName_01a01620-57c8-7b6d-9c2d-d48abe34569f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_01a01620-57c8-7443-ace4-016722c796ea" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityIncorporationStateCountryCode_01a01620-57c8-7443-ace4-016722c796ea" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_01a01620-57c8-730c-b847-eea51f935538" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityTaxIdentificationNumber_01a01620-57c8-730c-b847-eea51f935538" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_01a01620-57c8-7a8d-a4d8-951761e524ab" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityAddressAddressLine1_01a01620-57c8-7a8d-a4d8-951761e524ab" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_01a01620-57c8-7209-8263-937594120daf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityAddressAddressLine2_01a01620-57c8-7209-8263-937594120daf" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_01a01620-57c8-724c-adfc-b983bdc3b161" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityAddressCityOrTown_01a01620-57c8-724c-adfc-b983bdc3b161" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_01a01620-57c8-7b62-aa27-569ab846ff2f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityAddressStateOrProvince_01a01620-57c8-7b62-aa27-569ab846ff2f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_01a01620-57c8-7967-897a-1f6b5399987a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityAddressPostalZipCode_01a01620-57c8-7967-897a-1f6b5399987a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_01a01620-57c8-7b70-926d-198d003822ed" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_CityAreaCode_01a01620-57c8-7b70-926d-198d003822ed" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_01a01620-57c8-7d33-a8b2-13c2ea41db27" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_LocalPhoneNumber_01a01620-57c8-7d33-a8b2-13c2ea41db27" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_01a01620-57c8-791a-9be8-23f955b0a63f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_Security12bTitle_01a01620-57c8-791a-9be8-23f955b0a63f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_01a01620-57c8-7b50-a36b-183705223e97" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_TradingSymbol_01a01620-57c8-7b50-a36b-183705223e97" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_01a01620-57c8-7c49-96b6-67d158adc412" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_SecurityExchangeName_01a01620-57c8-7c49-96b6-67d158adc412" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_01a01620-57c8-7bd9-85e3-037f9f5c4de9" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityCurrentReportingStatus_01a01620-57c8-7bd9-85e3-037f9f5c4de9" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_01a01620-57c8-7192-a8bc-e7d6ae280ebb" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityInteractiveDataCurrent_01a01620-57c8-7192-a8bc-e7d6ae280ebb" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_01a01620-57c8-7432-b8db-1bdc506133cf" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityFilerCategory_01a01620-57c8-7432-b8db-1bdc506133cf" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_01a01620-57c8-7623-9e9b-9ad1f70a81a7" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntitySmallBusiness_01a01620-57c8-7623-9e9b-9ad1f70a81a7" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_01a01620-57c8-75fa-860e-c906d8686c31" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityEmergingGrowthCompany_01a01620-57c8-75fa-860e-c906d8686c31" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_01a01620-57c8-730d-a318-f65e872829e6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityShellCompany_01a01620-57c8-730d-a318-f65e872829e6" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_01a01620-57c8-7817-a744-2fddd5068d9c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_01a01620-57c8-7817-a744-2fddd5068d9c" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_01a01620-57c8-7c2e-9c76-f6183fc3cdbd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_EntityCentralIndexKey_01a01620-57c8-7c2e-9c76-f6183fc3cdbd" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_01a01620-57c8-7c9c-99ef-a168ec51a1d5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_AmendmentFlag_01a01620-57c8-7c9c-99ef-a168ec51a1d5" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_01a01620-57c8-7992-bff8-780d381fc305" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_CurrentFiscalYearEndDate_01a01620-57c8-7992-bff8-780d381fc305" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_01a01620-57c8-70f1-ba30-9b48fd26895b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentFiscalYearFocus_01a01620-57c8-70f1-ba30-9b48fd26895b" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_01a01620-57c8-77f7-956f-bea79155ccdc" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a01620-57c8-735d-b7b7-d66676a37cc5" xlink:to="loc_dei_DocumentFiscalPeriodFocus_01a01620-57c8-77f7-956f-bea79155ccdc" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITION" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITION"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITION" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-784f-af11-96bce52dea83" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-7e1a-a3e1-1b643b4f380f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-784f-af11-96bce52dea83" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-7e1a-a3e1-1b643b4f380f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7669-97c1-9dc76be1b790" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7e1a-a3e1-1b643b4f380f" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7669-97c1-9dc76be1b790" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7669-97c1-9dc76be1b790_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7669-97c1-9dc76be1b790" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7669-97c1-9dc76be1b790_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7fbf-9ea0-96d6315083c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-7669-97c1-9dc76be1b790" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7fbf-9ea0-96d6315083c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-74d9-b790-f0745bfd524d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7fbf-9ea0-96d6315083c5" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-74d9-b790-f0745bfd524d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-726e-a4aa-adf85c4a471c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7e1a-a3e1-1b643b4f380f" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-726e-a4aa-adf85c4a471c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-726e-a4aa-adf85c4a471c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-726e-a4aa-adf85c4a471c" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-726e-a4aa-adf85c4a471c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7607-8903-0f54c89cf69e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-726e-a4aa-adf85c4a471c" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7607-8903-0f54c89cf69e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-57c8-7780-bce8-ed39522fa93d" xlink:href="newt-20260930.xsd#newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7607-8903-0f54c89cf69e" xlink:to="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-57c8-7780-bce8-ed39522fa93d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-784f-af11-96bce52dea83" xlink:to="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Cash_01a01620-57c8-7a80-b3b3-b4961fc795af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_Cash_01a01620-57c8-7a80-b3b3-b4961fc795af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_01a01620-57c8-7f8b-8d62-32d6fa5e711e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_RestrictedCash_01a01620-57c8-7f8b-8d62-32d6fa5e711e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueFromBanks_01a01620-57c8-76fd-8b01-af8cbd4b4083" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DueFromBanks"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_DueFromBanks_01a01620-57c8-76fd-8b01-af8cbd4b4083" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_01a01620-57c8-796b-bafa-fb67d97ae9e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_01a01620-57c8-796b-bafa-fb67d97ae9e5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecurities_01a01620-57c8-7d56-81e5-e0fb79bf9fbb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MarketableSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_MarketableSecurities_01a01620-57c8-7d56-81e5-e0fb79bf9fbb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-57c8-7e89-92e8-b04b1a946b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansReceivableHeldForSaleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-57c8-7e89-92e8-b04b1a946b3a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-57c8-75c4-8088-5d8773b3fa4b" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-57c8-75c4-8088-5d8773b3fa4b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-71d3-9fe8-bd2e8c1e5b30" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-71d3-9fe8-bd2e8c1e5b30" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c8-7180-bc84-5ffcb1856ec4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c8-7180-bc84-5ffcb1856ec4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c8-7295-8cf5-d3bda0fa7572" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c8-7295-8cf5-d3bda0fa7572" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-7829-bcce-3fb404f625d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-7829-bcce-3fb404f625d8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_01a01620-57c8-7271-b923-9c22e6599e55" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_01a01620-57c8-7271-b923-9c22e6599e55" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_01a01620-57c8-7e50-96b3-e51c7d1484b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_ReceivablesFromBrokersDealersAndClearingOrganizations_01a01620-57c8-7e50-96b3-e51c7d1484b4" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualsInSecuritizationFairValue_01a01620-57c8-72fc-be76-f12a8a1964d2" xlink:href="newt-20260930.xsd#newt_ResidualsInSecuritizationFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_newt_ResidualsInSecuritizationFairValue_01a01620-57c8-72fc-be76-f12a8a1964d2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7eb3-ae85-dcaec18baf2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7eb3-ae85-dcaec18baf2d" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_01a01620-57c8-7424-8abd-180f645609e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_01a01620-57c8-7424-8abd-180f645609e9" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_01a01620-57c8-7969-b4ba-6a9cea914928" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_01a01620-57c8-7969-b4ba-6a9cea914928" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_01a01620-57c8-7981-845e-74bf062a7018" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_01a01620-57c8-7981-845e-74bf062a7018" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-57c8-7050-874a-f9f0f9a77226" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-57c8-7050-874a-f9f0f9a77226" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtAmortizedValue_01a01620-57c8-73b2-b008-8059462e6363" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtAmortizedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_ServicingAssetAtAmortizedValue_01a01620-57c8-73b2-b008-8059462e6363" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_01a01620-57c8-778b-abb8-8430420ff435" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_OtherAssets_01a01620-57c8-778b-abb8-8430420ff435" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_01a01620-57c8-7dc2-b6c8-a9d9947b8098" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_01a01620-57c8-7466-b691-f85da096d53e" xlink:to="loc_us-gaap_Assets_01a01620-57c8-7dc2-b6c8-a9d9947b8098" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-784f-af11-96bce52dea83" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:to="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract_01a01620-57c8-72be-ae03-219d01574436" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract_01a01620-57c8-72be-ae03-219d01574436" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_01a01620-57c8-73f8-a98d-fa985351f765" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract_01a01620-57c8-72be-ae03-219d01574436" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_01a01620-57c8-73f8-a98d-fa985351f765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilities_01a01620-57c8-7c2b-bc77-27c9ec6a6aac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract_01a01620-57c8-72be-ae03-219d01574436" xlink:to="loc_us-gaap_InterestBearingDepositLiabilities_01a01620-57c8-7c2b-bc77-27c9ec6a6aac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_01a01620-57c8-76cc-b4f8-ba3aedbc0ab7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositsInterestBearingAndNoninterestBearingAlternativeAbstract_01a01620-57c8-72be-ae03-219d01574436" xlink:to="loc_us-gaap_Deposits_01a01620-57c8-76cc-b4f8-ba3aedbc0ab7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a01620-57c8-7abc-9310-2175d157de4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_LongTermDebt_01a01620-57c8-7abc-9310-2175d157de4e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_01a01620-57c8-7140-b91b-c2fc8bbf29af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_OperatingLeaseLiability_01a01620-57c8-7140-b91b-c2fc8bbf29af" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_01a01620-57c8-77bc-bc97-8cedec25963b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_01a01620-57c8-77bc-bc97-8cedec25963b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DueToParticipants_01a01620-57c8-7b3a-83d4-177420a48a6d" xlink:href="newt-20260930.xsd#newt_DueToParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_newt_DueToParticipants_01a01620-57c8-7b3a-83d4-177420a48a6d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_01a01620-57c8-7afe-9dbd-e8f7d2c1b3fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsPayableAndOtherAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_AccountsPayableAndOtherAccruedLiabilities_01a01620-57c8-7afe-9dbd-e8f7d2c1b3fc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_01a01620-57c8-7a1c-b943-fec25b522221" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_01a01620-57c8-754f-ada9-a4e37c644f58" xlink:to="loc_us-gaap_Liabilities_01a01620-57c8-7a1c-b943-fec25b522221" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_01a01620-57c8-715d-ac42-38d1b418ba58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:to="loc_us-gaap_CommitmentsAndContingencies_01a01620-57c8-715d-ac42-38d1b418ba58" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:to="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_01a01620-57c8-70a2-a8c1-3e2e1ab1c857" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_PreferredStockValue_01a01620-57c8-70a2-a8c1-3e2e1ab1c857" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_01a01620-57c8-7c6e-b17f-f2090702b299" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_CommonStockValue_01a01620-57c8-7c6e-b17f-f2090702b299" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_01a01620-57c8-7ba1-82d9-70804baec0c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_01a01620-57c8-7ba1-82d9-70804baec0c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_01a01620-57c8-7762-82fc-de971371a920" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_AdditionalPaidInCapital_01a01620-57c8-7762-82fc-de971371a920" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a01620-57c8-7907-90a2-bb400d862832" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_01a01620-57c8-7907-90a2-bb400d862832" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a01620-57c8-7d1f-8fc4-94923e28b014" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_01a01620-57c8-78ce-b1d6-78cffe4f8957" xlink:to="loc_us-gaap_StockholdersEquity_01a01620-57c8-7d1f-8fc4-94923e28b014" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_01a01620-57c8-7b05-97da-8ea7d5292f02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_01a01620-57c8-7acb-8025-05ed0866cdd7" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_01a01620-57c8-7b05-97da-8ea7d5292f02" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITIONParenthetical" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITIONParenthetical"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFFINANCIALCONDITIONParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-734e-89ae-39efcd53f8bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-734e-89ae-39efcd53f8bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-79a9-b68d-655a72c03998" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-734e-89ae-39efcd53f8bb" xlink:to="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-79a9-b68d-655a72c03998" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-79a9-b68d-655a72c03998_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-79a9-b68d-655a72c03998" xlink:to="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-79a9-b68d-655a72c03998_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-79a8-a27d-612fd01fbd81" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-79a9-b68d-655a72c03998" xlink:to="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-79a8-a27d-612fd01fbd81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_01a01620-57c8-7d96-b5e7-bf2c804f8bf4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-79a8-a27d-612fd01fbd81" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_01a01620-57c8-7d96-b5e7-bf2c804f8bf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-73e0-939a-6d5c719b0c14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-734e-89ae-39efcd53f8bb" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-73e0-939a-6d5c719b0c14" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-73e0-939a-6d5c719b0c14_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-73e0-939a-6d5c719b0c14" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-73e0-939a-6d5c719b0c14_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7540-b696-612ae8faf627" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-73e0-939a-6d5c719b0c14" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7540-b696-612ae8faf627" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-7ebd-ad01-cf31da3d75ca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-7540-b696-612ae8faf627" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-7ebd-ad01-cf31da3d75ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_01a01620-57c8-7844-ac3c-1b685b33cf70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_RestrictedCash_01a01620-57c8-7844-ac3c-1b685b33cf70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-77a1-bc3a-df263153f535" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-77a1-bc3a-df263153f535" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_JointVenturesAndNoncontrolledInvestmentsAmortizedCost_01a01620-57c8-7b7a-a62d-e2bef969b371" xlink:href="newt-20260930.xsd#newt_JointVenturesAndNoncontrolledInvestmentsAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_newt_JointVenturesAndNoncontrolledInvestmentsAmortizedCost_01a01620-57c8-7b7a-a62d-e2bef969b371" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a01620-57c8-7a6a-8521-b1365d071f39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_LongTermDebt_01a01620-57c8-7a6a-8521-b1365d071f39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_01a01620-57c8-71d9-8655-561345388061" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_01a01620-57c8-71d9-8655-561345388061" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_01a01620-57c8-7fa7-80d0-c13715aa4be9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_01a01620-57c8-7fa7-80d0-c13715aa4be9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_01a01620-57c8-753c-a367-0bdea5259fff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_PreferredStockSharesIssued_01a01620-57c8-753c-a367-0bdea5259fff" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_01a01620-57c8-74e6-9b54-d1cb15718ed2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_01a01620-57c8-74e6-9b54-d1cb15718ed2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_01a01620-57c8-716d-b5ae-fc021fb1ddb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_01a01620-57c8-716d-b5ae-fc021fb1ddb2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_01a01620-57c8-74ec-89ee-963a33caf116" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_01a01620-57c8-74ec-89ee-963a33caf116" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_01a01620-57c8-7d25-849c-fb223bab1c81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_CommonStockSharesIssued_01a01620-57c8-7d25-849c-fb223bab1c81" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_01a01620-57c8-770d-bf17-52d46e6732fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e48-b8f2-bc387c268d8a" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_01a01620-57c8-770d-bf17-52d46e6732fa" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFINCOMEUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-7878-aa95-a6c01347b913" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-7878-aa95-a6c01347b913" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7c8d-be0b-741bf8bbc0c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7878-aa95-a6c01347b913" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7c8d-be0b-741bf8bbc0c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7c8d-be0b-741bf8bbc0c4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7c8d-be0b-741bf8bbc0c4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7c8d-be0b-741bf8bbc0c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7439-b0d9-684c4e158968" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7c8d-be0b-741bf8bbc0c4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7439-b0d9-684c4e158968" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NotesAndSecuritizationTrustsMember_01a01620-57c8-7cd6-bd85-59b6dafaccd3" xlink:href="newt-20260930.xsd#newt_NotesAndSecuritizationTrustsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7439-b0d9-684c4e158968" xlink:to="loc_newt_NotesAndSecuritizationTrustsMember_01a01620-57c8-7cd6-bd85-59b6dafaccd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_BankAndFederalHomeLoanBankBorrowingsMember_01a01620-57c8-786b-a0fb-cc6963eb0a2e" xlink:href="newt-20260930.xsd#newt_BankAndFederalHomeLoanBankBorrowingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7439-b0d9-684c4e158968" xlink:to="loc_newt_BankAndFederalHomeLoanBankBorrowingsMember_01a01620-57c8-786b-a0fb-cc6963eb0a2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_01a01620-57c8-78c9-9e9a-95483ca89b38" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:to="loc_us-gaap_InterestIncomeDebtSecuritiesAvailableForSaleOperating_01a01620-57c8-78c9-9e9a-95483ca89b38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_01a01620-57c8-776b-bb14-c25d3831b79a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndFeeIncomeLoansAndLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansAndLeases_01a01620-57c8-776b-bb14-c25d3831b79a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOther_01a01620-57c8-7117-9f79-acbe44a6ccad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:to="loc_us-gaap_InterestIncomeOther_01a01620-57c8-7117-9f79-acbe44a6ccad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperating_01a01620-57c8-78cd-b1ef-a1d0dfd05b75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_01a01620-57c8-79da-94dd-f748dc14b879" xlink:to="loc_us-gaap_InterestIncomeOperating_01a01620-57c8-78cd-b1ef-a1d0dfd05b75" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_01a01620-57c8-7dd9-8adc-9e5c3c804adf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_OperatingExpensesAbstract_01a01620-57c8-7dd9-8adc-9e5c3c804adf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDeposits_01a01620-57c8-7bc0-8e14-e5848fce9d03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_01a01620-57c8-7dd9-8adc-9e5c3c804adf" xlink:to="loc_us-gaap_InterestExpenseDeposits_01a01620-57c8-7bc0-8e14-e5848fce9d03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_01a01620-57c8-76b3-8716-f051c16a0ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_01a01620-57c8-7dd9-8adc-9e5c3c804adf" xlink:to="loc_us-gaap_InterestExpenseDebt_01a01620-57c8-76b3-8716-f051c16a0ba4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_01a01620-57c8-72f7-8f4a-ceb15b243de6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_01a01620-57c8-7dd9-8adc-9e5c3c804adf" xlink:to="loc_us-gaap_InterestExpenseOperating_01a01620-57c8-72f7-8f4a-ceb15b243de6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_01a01620-57c8-7965-8410-d22c6aa5f83c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_01a01620-57c8-7965-8410-d22c6aa5f83c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-57c8-77e3-a931-0d790870f6b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-57c8-77e3-a931-0d790870f6b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_01a01620-57c8-7e14-9c4a-b82cb5f0a7d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_01a01620-57c8-7e14-9c4a-b82cb5f0a7d0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeDividend_01a01620-57c8-72ef-b4c1-350ef1d555a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeDividend"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_us-gaap_InvestmentIncomeDividend_01a01620-57c8-72ef-b4c1-350ef1d555a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NetIncomeLossOnLoanServicingAsset_01a01620-57c8-7c84-97ee-09b30e51482b" xlink:href="newt-20260930.xsd#newt_NetIncomeLossOnLoanServicingAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_newt_NetIncomeLossOnLoanServicingAsset_01a01620-57c8-7c84-97ee-09b30e51482b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-57c8-7a1a-b458-1933f5f7d47b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-57c8-7a1a-b458-1933f5f7d47b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_01a01620-57c8-7dc6-8dc4-520c86b8dabb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_01a01620-57c8-7dc6-8dc4-520c86b8dabb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GainLossOnResidualsInSecuritizations_01a01620-57c8-75c9-a169-285a0f2c21eb" xlink:href="newt-20260930.xsd#newt_GainLossOnResidualsInSecuritizations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_newt_GainLossOnResidualsInSecuritizations_01a01620-57c8-75c9-a169-285a0f2c21eb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption_01a01620-57c8-7d70-ac77-a282281606f6" xlink:href="newt-20260930.xsd#newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption_01a01620-57c8-7d70-ac77-a282281606f6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ElectronicPaymentProcessingIncome_01a01620-57c8-717f-b784-7d5ad0e1a88e" xlink:href="newt-20260930.xsd#newt_ElectronicPaymentProcessingIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_newt_ElectronicPaymentProcessingIncome_01a01620-57c8-717f-b784-7d5ad0e1a88e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncomeOther_01a01620-57c8-7b15-a5f1-58625b6c61eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncomeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_us-gaap_NoninterestIncomeOther_01a01620-57c8-7b15-a5f1-58625b6c61eb" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_01a01620-57c8-70bd-8394-5ea41e875a4b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestIncomeAbstract_01a01620-57c8-779f-a784-7f2fc12e09d1" xlink:to="loc_us-gaap_NoninterestIncome_01a01620-57c8-70bd-8394-5ea41e875a4b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_01a01620-57c8-7ba2-a772-ba7f6256b025" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_LaborAndRelatedExpense_01a01620-57c8-7ba2-a772-ba7f6256b025" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ElectronicPaymentProcessingExpense_01a01620-57c8-7896-a771-0acf6d870565" xlink:href="newt-20260930.xsd#newt_ElectronicPaymentProcessingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_newt_ElectronicPaymentProcessingExpense_01a01620-57c8-7896-a771-0acf6d870565" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_01a01620-57c8-7217-910c-6c2a88fc684e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_ProfessionalFees_01a01620-57c8-7217-910c-6c2a88fc684e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LoanProcessingFeeOther_01a01620-57c8-7f82-b385-5df9800e30a9" xlink:href="newt-20260930.xsd#newt_LoanProcessingFeeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_newt_LoanProcessingFeeOther_01a01620-57c8-7f82-b385-5df9800e30a9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_01a01620-57c8-75ad-9ed5-28cf5aa7e40a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_01a01620-57c8-75ad-9ed5-28cf5aa7e40a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_01a090d7-e3e2-734d-943d-585e4d98a646" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_01a090d7-e3e2-734d-943d-585e4d98a646" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a01620-57c8-70e7-a456-4cde9893545d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a01620-57c8-70e7-a456-4cde9893545d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_01a01620-57c8-7201-a2d8-9af1309f6367" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoninterestExpenseAbstract_01a01620-57c8-75e8-a05e-e8555aa27b7b" xlink:to="loc_us-gaap_NoninterestExpense_01a01620-57c8-7201-a2d8-9af1309f6367" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossAttributableToParent_01a01620-57c8-706f-9c2b-a32b4a37c5a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_IncomeLossAttributableToParent_01a01620-57c8-706f-9c2b-a32b4a37c5a0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_01a01620-57c8-723b-a8be-2de8cd39518f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_01a01620-57c8-723b-a8be-2de8cd39518f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a01620-57c8-7685-b17e-d72d8c0616de" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_NetIncomeLoss_01a01620-57c8-7685-b17e-d72d8c0616de" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_01a01620-57c8-7294-8bf0-2b2ff541ff12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_DividendsPreferredStock_01a01620-57c8-7294-8bf0-2b2ff541ff12" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_01a01620-57c8-7400-b898-2869ed419d1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_01a01620-57c8-7400-b898-2869ed419d1e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_01a01620-57c8-7e44-8c9e-3f2d5a9ba128" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7e68-9dc3-6330b85e4d90" xlink:to="loc_us-gaap_EarningsPerShareAbstract_01a01620-57c8-7e44-8c9e-3f2d5a9ba128" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_01a01620-57c8-7efa-a2a4-b936017a26ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_01a01620-57c8-7e44-8c9e-3f2d5a9ba128" xlink:to="loc_us-gaap_EarningsPerShareBasic_01a01620-57c8-7efa-a2a4-b936017a26ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_01a01620-57c8-7d99-93f6-7be8f4b4e3c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_01a01620-57c8-7e44-8c9e-3f2d5a9ba128" xlink:to="loc_us-gaap_EarningsPerShareDiluted_01a01620-57c8-7d99-93f6-7be8f4b4e3c6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITYUNAUDITED" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITYUNAUDITED"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINSHAREHOLDERSEQUITYUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-7122-9d59-829a1304ca8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-7df8-b6d3-5657399e54e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7122-9d59-829a1304ca8f" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-7df8-b6d3-5657399e54e2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_01a01620-57c8-7b3e-8602-22992a27f2a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7df8-b6d3-5657399e54e2" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_01a01620-57c8-7b3e-8602-22992a27f2a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7b3e-8602-22992a27f2a8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_01a01620-57c8-7b3e-8602-22992a27f2a8" xlink:to="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7b3e-8602-22992a27f2a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_01a01620-57c8-7b3e-8602-22992a27f2a8" xlink:to="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_01a01620-57c8-719f-bc37-adad1ddbd6b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:to="loc_us-gaap_PreferredStockMember_01a01620-57c8-719f-bc37-adad1ddbd6b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_01a01620-57c8-76f7-994e-41fabf169d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:to="loc_us-gaap_CommonStockMember_01a01620-57c8-76f7-994e-41fabf169d2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_01a01620-57c8-74e6-a182-34fc800ffd73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:to="loc_us-gaap_RetainedEarningsMember_01a01620-57c8-74e6-a182-34fc800ffd73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_01a01620-57c8-7f6c-acd0-b3994acc83e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_01a01620-57c8-7f6c-acd0-b3994acc83e9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a01620-57c8-7b23-ba0e-d30275d7e08d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_01a01620-57c8-7ca9-8d8d-9c9041d5b547" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_01a01620-57c8-7b23-ba0e-d30275d7e08d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-72c6-bf2f-f328db01a80d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7df8-b6d3-5657399e54e2" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-72c6-bf2f-f328db01a80d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-72c6-bf2f-f328db01a80d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-72c6-bf2f-f328db01a80d" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-72c6-bf2f-f328db01a80d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-74a8-8845-a84cc993625c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-57c8-72c6-bf2f-f328db01a80d" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-74a8-8845-a84cc993625c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_01a01620-57c8-7bf7-98fe-b036b491c14d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-74a8-8845-a84cc993625c" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_01a01620-57c8-7bf7-98fe-b036b491c14d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-7618-8261-9422abf23458" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-57c8-74a8-8845-a84cc993625c" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_01a01620-57c8-7618-8261-9422abf23458" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7122-9d59-829a1304ca8f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_01a01620-57c8-7d95-8382-cbb30f6e537d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_01a01620-57c8-7d95-8382-cbb30f6e537d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a01620-57c8-73cb-9ed9-c66aca83be7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockholdersEquity_01a01620-57c8-73cb-9ed9-c66aca83be7b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_01a01620-57c8-7924-bef2-54dcdac105c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_01a01620-57c8-7924-bef2-54dcdac105c0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a01620-57c8-784b-adf5-134bbfc54c31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_01a01620-57c8-784b-adf5-134bbfc54c31" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DividendShareBasedPaymentSharesIssued_01a01620-57c8-70c3-af7d-3ee048fed581" xlink:href="newt-20260930.xsd#newt_DividendShareBasedPaymentSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_newt_DividendShareBasedPaymentSharesIssued_01a01620-57c8-70c3-af7d-3ee048fed581" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsShareBasedCompensation_01a090e2-25ba-79cd-b668-ca24379a682b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_DividendsShareBasedCompensation_01a090e2-25ba-79cd-b668-ca24379a682b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DividendShareBasedPaymentArrangementNetOfAccruedDividendsForfeited_01a01620-57c8-7ea0-bb43-9da5b15227e4" xlink:href="newt-20260930.xsd#newt_DividendShareBasedPaymentArrangementNetOfAccruedDividendsForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_newt_DividendShareBasedPaymentArrangementNetOfAccruedDividendsForfeited_01a01620-57c8-7ea0-bb43-9da5b15227e4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_01a01620-57c8-76a9-939a-c15e8f869b91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation_01a01620-57c8-76a9-939a-c15e8f869b91" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_01a01620-57c8-7adc-ba96-2daa521f5cc9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation_01a01620-57c8-7adc-ba96-2daa521f5cc9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_01a01620-57c8-73b8-a90c-f56c0b0f830c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_01a01620-57c8-73b8-a90c-f56c0b0f830c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_01a01620-57c8-74d9-ab9d-455d633b1211" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_01a01620-57c8-74d9-ab9d-455d633b1211" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_01a01620-57c8-7cd2-bdef-eb4c63ba28ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_01a01620-57c8-7cd2-bdef-eb4c63ba28ce" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_01a01620-57c8-77c6-861f-1df1643de933" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_01a01620-57c8-77c6-861f-1df1643de933" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_01a01620-57c8-7da3-8918-113d54378dad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_01a01620-57c8-7da3-8918-113d54378dad" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_01a01620-57c8-790d-ae63-1f488d0ad49f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_01a01620-57c8-790d-ae63-1f488d0ad49f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01a090e3-718a-7c00-96c0-9314c32689cc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01a090e3-718a-7c00-96c0-9314c32689cc" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_01a090e3-bc50-7724-b37f-5472a3a3941c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_01a090e3-bc50-7724-b37f-5472a3a3941c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement_01a090e6-4893-7eb1-a235-09f756398599" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement_01a090e6-4893-7eb1-a235-09f756398599" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement_01a090e6-8738-7619-b9ac-74a6c6c75252" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement_01a090e6-8738-7619-b9ac-74a6c6c75252" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_01a090ff-e744-7236-b38f-e6c758ba1dc9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_01a090ff-e744-7236-b38f-e6c758ba1dc9" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_01a01620-57c8-76f3-a7d0-6dac167dd7d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_DividendsCommonStock_01a01620-57c8-76f3-a7d0-6dac167dd7d4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_01a01620-57c8-7811-9767-87bb24a6dfca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_DividendsPreferredStock_01a01620-57c8-7811-9767-87bb24a6dfca" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a01620-57c8-7f9d-b6cb-24a773d1be37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_NetIncomeLoss_01a01620-57c8-7f9d-b6cb-24a773d1be37" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_01a01620-57c8-78fb-8d07-72e4c2ae91f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_01a01620-57c8-723c-803e-72e18fe33981" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_01a01620-57c8-78fb-8d07-72e4c2ae91f5" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_01a01620-57c8-7d58-b653-d347cb41face" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01a01620-57c8-71cc-9e52-86ad105d974e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_01a01620-57c8-78a2-aa1a-6c4fde372d18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITED" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-7ddd-be86-4d97197f1824" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-7ddd-be86-4d97197f1824" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7a65-a6a8-912474c1a5ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7ddd-be86-4d97197f1824" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7a65-a6a8-912474c1a5ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a65-a6a8-912474c1a5ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7a65-a6a8-912474c1a5ce" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a65-a6a8-912474c1a5ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7a65-a6a8-912474c1a5ce" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20338.375NotesMember_01a01620-57c8-7c8c-abdd-dae7c6054d0b" xlink:href="newt-20260930.xsd#newt_A20338.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:to="loc_newt_A20338.375NotesMember_01a01620-57c8-7c8c-abdd-dae7c6054d0b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-57c8-7ab7-a421-956c989e30fa" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:to="loc_newt_A2026NotesMember_01a01620-57c8-7ab7-a421-956c989e30fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2025500NotesMember_01a01620-57c8-74fc-b686-d2f9241910aa" xlink:href="newt-20260930.xsd#newt_A2025500NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:to="loc_newt_A2025500NotesMember_01a01620-57c8-74fc-b686-d2f9241910aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2030NotesMember_01a19e10-c287-76fb-b179-22281f334dd4" xlink:href="newt-20260930.xsd#newt_A2030NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:to="loc_newt_A2030NotesMember_01a19e10-c287-76fb-b179-22281f334dd4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a090ee-9922-7b18-9042-8a1b88345663" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a97-bb6f-dd9a5f511bb5" xlink:to="loc_newt_A20298.50NotesMember_01a090ee-9922-7b18-9042-8a1b88345663" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis_01a01620-57c8-74ab-af88-745a51977bd1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7ddd-be86-4d97197f1824" xlink:to="loc_us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis_01a01620-57c8-74ab-af88-745a51977bd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-74ab-af88-745a51977bd1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashOrPartNoncashDivestitureNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis_01a01620-57c8-74ab-af88-745a51977bd1" xlink:to="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-74ab-af88-745a51977bd1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-7aec-b462-379e590de160" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashOrPartNoncashDivestitureNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NoncashOrPartNoncashDivestituresByUniqueNameAxis_01a01620-57c8-74ab-af88-745a51977bd1" xlink:to="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-7aec-b462-379e590de160" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConsiderationStockAcquiredMember_01a01620-57c8-76bd-b61f-5b78e230dd5a" xlink:href="newt-20260930.xsd#newt_ConsiderationStockAcquiredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-7aec-b462-379e590de160" xlink:to="loc_newt_ConsiderationStockAcquiredMember_01a01620-57c8-76bd-b61f-5b78e230dd5a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConsiderationEarnOutReceivableMember_01a01620-57c8-7b1f-870b-762c4d4fbdd9" xlink:href="newt-20260930.xsd#newt_ConsiderationEarnOutReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NoncashOrPartNoncashDivestitureNameDomain_01a01620-57c8-7aec-b462-379e590de160" xlink:to="loc_newt_ConsiderationEarnOutReceivableMember_01a01620-57c8-7b1f-870b-762c4d4fbdd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-7328-8a94-8b5e985f6372" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-7328-8a94-8b5e985f6372" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a01620-57c8-72cd-b5a5-961e77814cd5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-7328-8a94-8b5e985f6372" xlink:to="loc_us-gaap_NetIncomeLoss_01a01620-57c8-72cd-b5a5-961e77814cd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:href="newt-20260930.xsd#newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-7328-8a94-8b5e985f6372" xlink:to="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7a5f-a195-b99135d97f81" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7a5f-a195-b99135d97f81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption_01a01620-57c8-78e7-9920-0c484d116935" xlink:href="newt-20260930.xsd#newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_UnrealizedGainLossOnSalesOfLoansNetFairValueOption_01a01620-57c8-78e7-9920-0c484d116935" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GainLossOnResidualsInSecuritizations_01a01620-57c8-780d-bf63-eed1a31427fd" xlink:href="newt-20260930.xsd#newt_GainLossOnResidualsInSecuritizations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_GainLossOnResidualsInSecuritizations_01a01620-57c8-780d-bf63-eed1a31427fd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GainLossOnLoanServicingAssets_01a01620-57c8-7afe-b960-67de1e6f6ed4" xlink:href="newt-20260930.xsd#newt_GainLossOnLoanServicingAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_GainLossOnLoanServicingAssets_01a01620-57c8-7afe-b960-67de1e6f6ed4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_01a01620-57c8-73a3-86e6-3527b12925fc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_01a01620-57c8-73a3-86e6-3527b12925fc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSalesOfLoansNet_01a01620-57c8-7e47-955e-65bb8a52d711" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSalesOfLoansNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_GainLossOnSalesOfLoansNet_01a01620-57c8-7e47-955e-65bb8a52d711" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_01a01620-57c8-7031-8045-bab9d50b346c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_01a01620-57c8-7031-8045-bab9d50b346c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GainLossOnExtinguishmentOfDebtNetOfDeferredFinancingCostsExpensed_01a090eb-ae0f-71e0-b59f-4e13c9296ab3" xlink:href="newt-20260930.xsd#newt_GainLossOnExtinguishmentOfDebtNetOfDeferredFinancingCostsExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_GainLossOnExtinguishmentOfDebtNetOfDeferredFinancingCostsExpensed_01a090eb-ae0f-71e0-b59f-4e13c9296ab3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_01a01620-57c8-7e95-a3b7-3d06f0f40b74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_01a01620-57c8-7e95-a3b7-3d06f0f40b74" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-57c8-7127-83e3-a74bb4a09f33" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-57c8-7127-83e3-a74bb4a09f33" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LowerOfCostOrMarketAdjustment_01a01620-57c8-7e50-bcbb-6bc606c9edc3" xlink:href="newt-20260930.xsd#newt_LowerOfCostOrMarketAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_LowerOfCostOrMarketAdjustment_01a01620-57c8-7e50-bcbb-6bc606c9edc3" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_01a01620-57c8-7146-b81e-055f89462748" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_01a01620-57c8-7146-b81e-055f89462748" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_01a01620-57c8-7285-8882-bb7a7e2428ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_ShareBasedCompensation_01a01620-57c8-7285-8882-bb7a7e2428ae" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_01a01620-57c8-7e18-9384-a4b757de1e7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_01a01620-57c8-7e18-9384-a4b757de1e7c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_01a01620-57c8-7d85-a597-051a142d1a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_01a01620-57c8-7d85-a597-051a142d1a8a" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfLoansHeldForSale_01a01620-57c8-7ef2-a4a4-61496512586a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfLoansHeldForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_ProceedsFromSaleOfLoansHeldForSale_01a01620-57c8-7ef2-a4a4-61496512586a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToPurchaseLoansHeldForSale_01a01620-57c8-7a58-bf14-f9d04caaef6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToPurchaseLoansHeldForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_PaymentsToPurchaseLoansHeldForSale_01a01620-57c8-7a58-bf14-f9d04caaef6d" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsForFundingOfLoansHeldForSale_01a01620-57c8-7f4a-a0e2-508a0edd3a39" xlink:href="newt-20260930.xsd#newt_PaymentsForFundingOfLoansHeldForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_PaymentsForFundingOfLoansHeldForSale_01a01620-57c8-7f4a-a0e2-508a0edd3a39" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ProceedsFromPrincipalReceivedOnLoansHeldForSale_01a01620-57c8-7f6a-a839-8bb1bfed931f" xlink:href="newt-20260930.xsd#newt_ProceedsFromPrincipalReceivedOnLoansHeldForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_newt_ProceedsFromPrincipalReceivedOnLoansHeldForSale_01a01620-57c8-7f6a-a839-8bb1bfed931f" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_01a01620-57c8-7cec-89a4-7b90620f44c3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_01a01620-57c8-7cec-89a4-7b90620f44c3" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_AdjustmentsToReconcileNetAssetsFromOperationsToCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-71ba-ad82-811672ec6ca9" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInBrokerageReceivables_01a01620-57c8-7c9e-9719-295c709a1017" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInBrokerageReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:to="loc_us-gaap_IncreaseDecreaseInBrokerageReceivables_01a01620-57c8-7c9e-9719-295c709a1017" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_01a01620-57c8-759a-8e08-e9ecdb0d3799" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingAssets_01a01620-57c8-759a-8e08-e9ecdb0d3799" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_IncreaseDecreaseInDueToParticipants_01a01620-57c8-79e7-9556-7a4dfc9914fd" xlink:href="newt-20260930.xsd#newt_IncreaseDecreaseInDueToParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:to="loc_newt_IncreaseDecreaseInDueToParticipants_01a01620-57c8-79e7-9556-7a4dfc9914fd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_01a01620-57c8-76e2-8f89-3d8b952d2271" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_01a01620-57c8-70fe-a67e-02e881a9c75c" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_01a01620-57c8-76e2-8f89-3d8b952d2271" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a01620-57c8-721d-9f20-f6b3257fe144" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_01a01620-57c8-7328-8a94-8b5e985f6372" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_01a01620-57c8-721d-9f20-f6b3257fe144" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ProceedsFromLoansHeldForInvestmentAtFairValue_01a01620-57c8-7a6c-a14d-2d785c15df05" xlink:href="newt-20260930.xsd#newt_ProceedsFromLoansHeldForInvestmentAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_ProceedsFromLoansHeldForInvestmentAtFairValue_01a01620-57c8-7a6c-a14d-2d785c15df05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsToAcquireLoansHeldForInvestmentAtFairValue_01a01620-57c8-703a-9ed0-13fe0125d0bd" xlink:href="newt-20260930.xsd#newt_PaymentsToAcquireLoansHeldForInvestmentAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_PaymentsToAcquireLoansHeldForInvestmentAtFairValue_01a01620-57c8-703a-9ed0-13fe0125d0bd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsToAcquireLoansReceivableHeldAtFairValue_01a1a781-d1ad-7f72-8726-65f376441a83" xlink:href="newt-20260930.xsd#newt_PaymentsToAcquireLoansReceivableHeldAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_PaymentsToAcquireLoansReceivableHeldAtFairValue_01a1a781-d1ad-7f72-8726-65f376441a83" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsToAcquireLoansReceivableHeldAtAmortizedCost_01a01620-57c8-74a0-9907-0e4ed4b3c016" xlink:href="newt-20260930.xsd#newt_PaymentsToAcquireLoansReceivableHeldAtAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_PaymentsToAcquireLoansReceivableHeldAtAmortizedCost_01a01620-57c8-74a0-9907-0e4ed4b3c016" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_01a01620-57c8-733d-8013-34830e566265" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromDivestitureOfBusinesses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_ProceedsFromDivestitureOfBusinesses_01a01620-57c8-733d-8013-34830e566265" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsForContributionsToJointVenturesAndNoncontrolledInvestments_01a01620-57c8-7a74-91d0-bb4e2be77ccd" xlink:href="newt-20260930.xsd#newt_PaymentsForContributionsToJointVenturesAndNoncontrolledInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_PaymentsForContributionsToJointVenturesAndNoncontrolledInvestments_01a01620-57c8-7a74-91d0-bb4e2be77ccd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_01a01620-57c8-70f9-b424-14afdb922f40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_01a01620-57c8-70f9-b424-14afdb922f40" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_01a01620-57c8-76ed-b2b8-b40582dac35b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_01a01620-57c8-76ed-b2b8-b40582dac35b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInLoansToFederalHomeLoanBanks_01a01620-57c8-779c-a85c-3f87cbe8e77b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInLoansToFederalHomeLoanBanks"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_IncreaseDecreaseInLoansToFederalHomeLoanBanks_01a01620-57c8-779c-a85c-3f87cbe8e77b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsToAcquireFederalHomeLoanBankAndFederalReserveBankStock_01a01620-57c8-7c9a-8b4e-bc6907f06bb7" xlink:href="newt-20260930.xsd#newt_PaymentsToAcquireFederalHomeLoanBankAndFederalReserveBankStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_PaymentsToAcquireFederalHomeLoanBankAndFederalReserveBankStock_01a01620-57c8-7c9a-8b4e-bc6907f06bb7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ProceedsFromSaleOfPaymentsToAcquireDebtSecuritiesAvailableForSale_01a01620-57c8-7e51-96e3-774e2b528e4b" xlink:href="newt-20260930.xsd#newt_ProceedsFromSaleOfPaymentsToAcquireDebtSecuritiesAvailableForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_newt_ProceedsFromSaleOfPaymentsToAcquireDebtSecuritiesAvailableForSale_01a01620-57c8-7e51-96e3-774e2b528e4b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_01a01620-57c8-7fd9-83b2-8a1ccbeb8df0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_01a01620-57c8-7fd9-83b2-8a1ccbeb8df0" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a01620-57c8-7d86-908a-f7616e994c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_01a01620-57c8-71cf-8072-6d45b6dc08ec" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_01a01620-57c8-7d86-908a-f7616e994c6f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromNotesPayable_01a01620-57c8-7e9a-8a18-4e513e299b8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromNotesPayable_01a01620-57c8-7e9a-8a18-4e513e299b8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfNotesPayable_01a01620-57c8-7879-aeea-9345a9b1b9bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfNotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_RepaymentsOfNotesPayable_01a01620-57c8-7879-aeea-9345a9b1b9bc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_IncreaseDecreaseInDepositLiabilities_01a01620-57c8-7b7d-bc41-4ff58d732d7d" xlink:href="newt-20260930.xsd#newt_IncreaseDecreaseInDepositLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_IncreaseDecreaseInDepositLiabilities_01a01620-57c8-7b7d-bc41-4ff58d732d7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RepaymentOfFederalHomeLoanBankAdvances_01a01620-57c8-7fae-b47a-0028f0e30b0b" xlink:href="newt-20260930.xsd#newt_RepaymentOfFederalHomeLoanBankAdvances"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_RepaymentOfFederalHomeLoanBankAdvances_01a01620-57c8-7fae-b47a-0028f0e30b0b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_01a090ee-3c48-76a2-91f9-4000ad510cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_01a090ee-3c48-76a2-91f9-4000ad510cbf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_01a090ee-3c48-7cbc-804f-00d52a14cb63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_01a090ee-3c48-7cbc-804f-00d52a14cb63" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ProceedsFromPurchaseAndExchangeAgreement_01a090ee-3c48-7067-8026-bf28621c009d" xlink:href="newt-20260930.xsd#newt_ProceedsFromPurchaseAndExchangeAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_ProceedsFromPurchaseAndExchangeAgreement_01a090ee-3c48-7067-8026-bf28621c009d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsForRepurchaseOfCommonStockShareRepurchasePlan_01a01620-57c8-7d81-aea3-eb034af95c7f" xlink:href="newt-20260930.xsd#newt_PaymentsForRepurchaseOfCommonStockShareRepurchasePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_PaymentsForRepurchaseOfCommonStockShareRepurchasePlan_01a01620-57c8-7d81-aea3-eb034af95c7f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfMediumTermNotes_01a01620-57c8-7b56-9bd0-ead7f2fc0153" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfMediumTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfMediumTermNotes_01a01620-57c8-7b56-9bd0-ead7f2fc0153" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-57c8-7cd9-86d3-8c0b65a5656d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfMediumTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-57c8-7cd9-86d3-8c0b65a5656d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsToPurchaseMediumTermNote_01a090ee-9922-75d1-a0a1-1233388ca6cd" xlink:href="newt-20260930.xsd#newt_PaymentsToPurchaseMediumTermNote"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_PaymentsToPurchaseMediumTermNote_01a090ee-9922-75d1-a0a1-1233388ca6cd" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfSecuredDebt_01a01620-57c8-7893-a0c9-19a28784712f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_RepaymentsOfSecuredDebt_01a01620-57c8-7893-a0c9-19a28784712f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_01a01620-57c8-7254-98be-e9ce32326a62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSecuredDebt_01a01620-57c8-7254-98be-e9ce32326a62" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_01a01620-57c8-7487-a297-5b9947f5c0ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_PaymentsOfDividends_01a01620-57c8-7487-a297-5b9947f5c0ee" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsOfDeferredFinancingCosts_01a01620-57c8-7339-9822-43a439737fd1" xlink:href="newt-20260930.xsd#newt_PaymentsOfDeferredFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_newt_PaymentsOfDeferredFinancingCosts_01a01620-57c8-7339-9822-43a439737fd1" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockPlans_01a01620-57c8-74fd-976d-25e190addc91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromStockPlans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_ProceedsFromStockPlans_01a01620-57c8-74fd-976d-25e190addc91" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_01a01620-57c8-7e37-84e6-d55ff4d048e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_01a01620-57c8-7e37-84e6-d55ff4d048e6" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a01620-57c8-719d-8440-e1986e01c5d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_01a01620-57c8-702b-94a5-4d0293ae70fe" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_01a01620-57c8-719d-8440-e1986e01c5d4" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a01620-57c8-77e2-98aa-5b13d5e3967c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_01a01620-57c8-77e2-98aa-5b13d5e3967c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_01a01620-57c8-704d-8b81-077d4b3c60f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_01a01620-57c8-704d-8b81-077d4b3c60f4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_01a01620-57c8-7b71-b312-e831df52daac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferOfOtherRealEstate_01a01620-57c8-79cd-9f3c-469e341a2b88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferOfOtherRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:to="loc_us-gaap_TransferOfOtherRealEstate_01a01620-57c8-79cd-9f3c-469e341a2b88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-57c8-7aab-b7ed-676ada18eff1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:to="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-57c8-7aab-b7ed-676ada18eff1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DividendsIncurredButNotYetPaid_01a01620-57c8-7052-b9db-1882c3933cd6" xlink:href="newt-20260930.xsd#newt_DividendsIncurredButNotYetPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:to="loc_newt_DividendsIncurredButNotYetPaid_01a01620-57c8-7052-b9db-1882c3933cd6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1_01a01620-57c8-7d5c-a04a-a238f66edc44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:to="loc_us-gaap_NoncashOrPartNoncashDivestitureAmountOfConsiderationReceived1_01a01620-57c8-7d5c-a04a-a238f66edc44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture_01a090f7-3239-7997-95aa-1d3177584417" xlink:href="newt-20260930.xsd#newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CashFlowNoncashInvestingAndFinancingActivitiesDisclosureAbstract_01a01620-57c8-7ade-a0a4-d38fcf6bab62" xlink:to="loc_newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture_01a090f7-3239-7997-95aa-1d3177584417" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_01a01620-57c8-7824-8a7f-d96ee0c60727" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SupplementalCashFlowInformationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ad6-a220-eedc92c0b5b6" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_01a01620-57c8-7824-8a7f-d96ee0c60727" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_01a01620-57c8-7924-9f89-38151e789412" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_01a01620-57c8-7824-8a7f-d96ee0c60727" xlink:to="loc_us-gaap_InterestPaidNet_01a01620-57c8-7924-9f89-38151e789412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_01a01620-57c8-7dc1-bc41-02889c8ddaa6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_01a01620-57c8-7824-8a7f-d96ee0c60727" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_01a01620-57c8-7dc1-bc41-02889c8ddaa6" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITEDParenthetical" xlink:type="simple" xlink:href="newt-20260930.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITEDParenthetical"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSUNAUDITEDParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_01a01620-57c8-7ea6-996b-2ccb6cf70534" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_01a01620-57c8-7c95-b813-8f1ac7d63a15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ea6-996b-2ccb6cf70534" xlink:to="loc_us-gaap_StatementTable_01a01620-57c8-7c95-b813-8f1ac7d63a15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-738c-9ed5-ac9c5768f8a5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7c95-b813-8f1ac7d63a15" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-738c-9ed5-ac9c5768f8a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-738c-9ed5-ac9c5768f8a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-738c-9ed5-ac9c5768f8a5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-738c-9ed5-ac9c5768f8a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-738c-9ed5-ac9c5768f8a5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20338.375NotesMember_01a01620-57c8-7faf-b09a-3ddb08dcd017" xlink:href="newt-20260930.xsd#newt_A20338.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:to="loc_newt_A20338.375NotesMember_01a01620-57c8-7faf-b09a-3ddb08dcd017" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-57c8-7924-86f9-583d300896f8" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:to="loc_newt_A2026NotesMember_01a01620-57c8-7924-86f9-583d300896f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2025500NotesMember_01a01620-57c8-7f7d-82cb-30b5c5c7454b" xlink:href="newt-20260930.xsd#newt_A2025500NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:to="loc_newt_A2025500NotesMember_01a01620-57c8-7f7d-82cb-30b5c5c7454b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a09105-493c-7d5a-9a5c-4a70c2bfbf35" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7f2e-95de-765978efa53c" xlink:to="loc_newt_A20298.50NotesMember_01a09105-493c-7d5a-9a5c-4a70c2bfbf35" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-74b5-a307-e6430aece5f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_01a01620-57c8-7c95-b813-8f1ac7d63a15" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-74b5-a307-e6430aece5f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-74b5-a307-e6430aece5f0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-74b5-a307-e6430aece5f0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-74b5-a307-e6430aece5f0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-73d6-a4fb-bea21bfcf8b4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-74b5-a307-e6430aece5f0" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-73d6-a4fb-bea21bfcf8b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-57c8-7a97-9581-ca65cdc69681" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-73d6-a4fb-bea21bfcf8b4" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-57c8-7a97-9581-ca65cdc69681" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a19e0d-7598-793e-a848-6e66d671365f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_01a01620-57c8-7ea6-996b-2ccb6cf70534" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a19e0d-7598-793e-a848-6e66d671365f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SECURITIZATIONSANDVARIABLEINTERESTENTITIESNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SECURITIZATIONSANDVARIABLEINTERESTENTITIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SECURITIZATIONSANDVARIABLEINTERESTENTITIESNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7472-abdc-0be494739277" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7472-abdc-0be494739277" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7358-aaaf-2d30200cd584" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7472-abdc-0be494739277" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7358-aaaf-2d30200cd584" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7358-aaaf-2d30200cd584_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7358-aaaf-2d30200cd584" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7358-aaaf-2d30200cd584_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7358-aaaf-2d30200cd584" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7074-98c0-58ac6e6b57df" xlink:href="newt-20260930.xsd#newt_TSONotesClassANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7074-98c0-58ac6e6b57df" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-7af9-8d2d-3d8d3fb985df" xlink:href="newt-20260930.xsd#newt_TSONotesClassBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-7af9-8d2d-3d8d3fb985df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassCNotesMember_01a01620-57c8-7b30-8e0b-fb32a38cd03d" xlink:href="newt-20260930.xsd#newt_TSONotesClassCNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_TSONotesClassCNotesMember_01a01620-57c8-7b30-8e0b-fb32a38cd03d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsClassAMember_01a01620-57c8-7e88-a270-aad723a1a7a8" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsClassAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_SecuritizationTrustsClassAMember_01a01620-57c8-7e88-a270-aad723a1a7a8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsClassBMember_01a01620-57c8-72b0-94af-f235fc51d6c1" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsClassBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_SecuritizationTrustsClassBMember_01a01620-57c8-72b0-94af-f235fc51d6c1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsClassCMember_01a01620-57c8-773c-ba8e-b46419d6e313" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsClassCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7001-969e-b30d5f90c3a6" xlink:to="loc_newt_SecuritizationTrustsClassCMember_01a01620-57c8-773c-ba8e-b46419d6e313" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-7a27-b288-277f144d7956" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7472-abdc-0be494739277" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-7a27-b288-277f144d7956" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-7a27-b288-277f144d7956_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-7a27-b288-277f144d7956" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-7a27-b288-277f144d7956_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-70fe-8c9a-398c5bffbb51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-57c8-7a27-b288-277f144d7956" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-70fe-8c9a-398c5bffbb51" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_01a01620-57c8-7203-9a5a-4c183cdd80ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-57c8-70fe-8c9a-398c5bffbb51" xlink:to="loc_us-gaap_SecuredDebtMember_01a01620-57c8-7203-9a5a-4c183cdd80ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NumberOfLoanSecuritizations_01a01620-57c8-72c5-a91b-22f0c3c95286" xlink:href="newt-20260930.xsd#newt_NumberOfLoanSecuritizations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_NumberOfLoanSecuritizations_01a01620-57c8-72c5-a91b-22f0c3c95286" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NotesSoldValue_01a01620-57c8-78c0-8513-09a226440541" xlink:href="newt-20260930.xsd#newt_NotesSoldValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_NotesSoldValue_01a01620-57c8-78c0-8513-09a226440541" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NotesSoldCollateralValue_01a01620-57c8-7e61-ad9e-f0d6459c12ae" xlink:href="newt-20260930.xsd#newt_NotesSoldCollateralValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_NotesSoldCollateralValue_01a01620-57c8-7e61-ad9e-f0d6459c12ae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_FinancingReceivableBeforeAllowanceForCreditLossAverageYield_01a01620-57c8-728e-93c9-ecbb8b281e7c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_FinancingReceivableBeforeAllowanceForCreditLossAverageYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_srt_FinancingReceivableBeforeAllowanceForCreditLossAverageYield_01a01620-57c8-728e-93c9-ecbb8b281e7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAdvanceRate_01a01620-57c8-726e-a132-6e505a07baeb" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossAdvanceRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAdvanceRate_01a01620-57c8-726e-a132-6e505a07baeb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-57c8-78f5-859f-c1603a1b8900" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-57c8-78f5-859f-c1603a1b8900" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7178-9f33-55a3a9c358ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCollateralAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7178-9f33-55a3a9c358ea" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentYieldPercentage_01a01620-57c8-7f3d-bd01-57b8c41a6205" xlink:href="newt-20260930.xsd#newt_DebtInstrumentYieldPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_DebtInstrumentYieldPercentage_01a01620-57c8-7f3d-bd01-57b8c41a6205" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentAverageYieldPercentage_01a01620-57c8-71a6-b00d-a74e5e80734a" xlink:href="newt-20260930.xsd#newt_DebtInstrumentAverageYieldPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_DebtInstrumentAverageYieldPercentage_01a01620-57c8-71a6-b00d-a74e5e80734a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentAdvanceRatePercentage_01a01620-57c8-73bb-8036-b94cee80d9d0" xlink:href="newt-20260930.xsd#newt_DebtInstrumentAdvanceRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7818-a5dd-b6cb46a77e99" xlink:to="loc_newt_DebtInstrumentAdvanceRatePercentage_01a01620-57c8-73bb-8036-b94cee80d9d0" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SECURITIZATIONSANDVARIABLEINTERESTENTITIESConsolidatedVIEsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SECURITIZATIONSANDVARIABLEINTERESTENTITIESConsolidatedVIEsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SECURITIZATIONSANDVARIABLEINTERESTENTITIESConsolidatedVIEsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7a15-8c87-d5fd88a35c73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7a15-8c87-d5fd88a35c73" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-7cca-88de-257c74091cae" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_01a01620-57c8-7a15-8c87-d5fd88a35c73" xlink:to="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-7cca-88de-257c74091cae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-7cca-88de-257c74091cae_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-7cca-88de-257c74091cae" xlink:to="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-7cca-88de-257c74091cae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-7783-a843-ced36f4e0554" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_01a01620-57c8-7cca-88de-257c74091cae" xlink:to="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-7783-a843-ced36f4e0554" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_01a01620-57c8-701c-aa4d-c9663aa5f2a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_01a01620-57c8-7783-a843-ced36f4e0554" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_01a01620-57c8-701c-aa4d-c9663aa5f2a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_01a01620-57c8-738f-b0e4-066f81eb4db4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_us-gaap_RestrictedCash_01a01620-57c8-738f-b0e4-066f81eb4db4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-7ddf-8d27-2512a0a7abc1" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c8-7ddf-8d27-2512a0a7abc1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_01a01620-57c8-70b9-9857-5155073c6e2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_us-gaap_Assets_01a01620-57c8-70b9-9857-5155073c6e2a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a01620-57c8-707a-af1a-e123e0b6ca7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_us-gaap_LongTermDebt_01a01620-57c8-707a-af1a-e123e0b6ca7f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_01a01620-57c8-76c7-afa7-0a32a6175144" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_01a01620-57c8-7b41-81c9-faa1959fc4e1" xlink:to="loc_us-gaap_Liabilities_01a01620-57c8-76c7-afa7-0a32a6175144" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSInvestmentPortfolioDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSInvestmentPortfolioDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSInvestmentPortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7421-9fbe-3c8760c4665b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b55-a04d-9bf274a36632" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7421-9fbe-3c8760c4665b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b55-a04d-9bf274a36632" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_01a01620-57c8-7b94-a778-ecdd000bff3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b55-a04d-9bf274a36632" xlink:to="loc_us-gaap_InvestmentTypeAxis_01a01620-57c8-7b94-a778-ecdd000bff3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-7b94-a778-ecdd000bff3b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_01a01620-57c8-7b94-a778-ecdd000bff3b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-7b94-a778-ecdd000bff3b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_01a01620-57c8-7b94-a778-ecdd000bff3b" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualValueOfSecuredAssetMember_01a01620-57c8-73b2-af21-8aa9b50858af" xlink:href="newt-20260930.xsd#newt_ResidualValueOfSecuredAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:to="loc_newt_ResidualValueOfSecuredAssetMember_01a01620-57c8-73b2-af21-8aa9b50858af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtSecuritiesAvailableForSaleMember_01a01620-57c8-7f16-8e99-de241ee81360" xlink:href="newt-20260930.xsd#newt_DebtSecuritiesAvailableForSaleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:to="loc_newt_DebtSecuritiesAvailableForSaleMember_01a01620-57c8-7f16-8e99-de241ee81360" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FederalHomeLoanBankAndFederalReserveBankStockMember_01a01620-57c8-7810-b093-647cd6436200" xlink:href="newt-20260930.xsd#newt_FederalHomeLoanBankAndFederalReserveBankStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:to="loc_newt_FederalHomeLoanBankAndFederalReserveBankStockMember_01a01620-57c8-7810-b093-647cd6436200" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TotalInvestmentsMember_01a01620-57c8-7de5-a8a9-5252e50e0632" xlink:href="newt-20260930.xsd#newt_TotalInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_01a01620-57c8-70ca-a9c6-ce380f80054e" xlink:to="loc_newt_TotalInvestmentsMember_01a01620-57c8-7de5-a8a9-5252e50e0632" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-7c80-a2a3-28c2a6a29921" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b55-a04d-9bf274a36632" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-7c80-a2a3-28c2a6a29921" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7c80-a2a3-28c2a6a29921_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-7c80-a2a3-28c2a6a29921" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7c80-a2a3-28c2a6a29921_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7db8-bb01-be486d5d6e2b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-7c80-a2a3-28c2a6a29921" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7db8-bb01-be486d5d6e2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-57c8-7d35-a413-135074240441" xlink:href="newt-20260930.xsd#newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-7db8-bb01-be486d5d6e2b" xlink:to="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-57c8-7d35-a413-135074240441" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_01a01620-57c8-7233-9ba0-9a8fd05c3e44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7421-9fbe-3c8760c4665b" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_01a01620-57c8-7233-9ba0-9a8fd05c3e44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7d1c-be46-ff705e17200f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7421-9fbe-3c8760c4665b" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7d1c-be46-ff705e17200f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-728e-bbee-8ff2a4488788_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-728e-bbee-8ff2a4488788_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7199-9b13-fe4b28f5bdf0" xlink:href="newt-20260930.xsd#newt_NewtekConventionalLendingLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:to="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7199-9b13-fe4b28f5bdf0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-57c8-7f99-acda-e69153f6d4d2_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:to="loc_dei_EntityDomain_01a01620-57c8-7f99-acda-e69153f6d4d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:to="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekCommercialLendingMember_01a01620-57c8-7900-8f4d-19c0b2cafe0e" xlink:href="newt-20260930.xsd#newt_NewtekCommercialLendingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_NewtekCommercialLendingMember_01a01620-57c8-7900-8f4d-19c0b2cafe0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-7383-bd4d-9bd6ef626264" xlink:href="newt-20260930.xsd#newt_ConventionalLendingTCPHoldingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-7383-bd4d-9bd6ef626264" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekALPHoldingsMember_01a01620-57c8-77ab-aaed-eeaf72640f57" xlink:href="newt-20260930.xsd#newt_NewtekALPHoldingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_NewtekALPHoldingsMember_01a01620-57c8-77ab-aaed-eeaf72640f57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-727d-a173-dc01b10df618_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-727d-a173-dc01b10df618_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7054-be58-024639fc84f0" xlink:href="newt-20260930.xsd#newt_NewtekConventionalLendingLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:to="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7054-be58-024639fc84f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7e7f-bed6-b430f12e6f89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7e7f-bed6-b430f12e6f89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-7025-a578-32e01bd28e51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-7025-a578-32e01bd28e51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-77c6-b0d0-cd354509fa4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-77c6-b0d0-cd354509fa4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7464-8a96-7ac40e2a9763" xlink:href="newt-20260930.xsd#newt_NewtekTechnologySolutionsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:to="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7464-8a96-7ac40e2a9763" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-70e0-ae16-bfb0b20bc708_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-70e0-ae16-bfb0b20bc708_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-77dc-9f3e-8597e982fa67" xlink:href="newt-20260930.xsd#newt_ConventionalLendingTCPHoldingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:to="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-77dc-9f3e-8597e982fa67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis_01a01620-57c8-780a-b4ed-3857854e0a75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_InvestmentIdentifierAxis_01a01620-57c8-780a-b4ed-3857854e0a75" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7e32-815a-dd861843a772_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7e32-815a-dd861843a772_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7054-86b6-6eb61e5cde46" xlink:href="newt-20260930.xsd#newt_TSONotesClassANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7054-86b6-6eb61e5cde46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-71e6-8423-9aaf418aac94" xlink:href="newt-20260930.xsd#newt_TSONotesClassBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-71e6-8423-9aaf418aac94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesMember_01a01620-57c8-765c-8065-22541b39c7f9" xlink:href="newt-20260930.xsd#newt_TSONotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesMember_01a01620-57c8-765c-8065-22541b39c7f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_01a01620-57c8-7d7a-932a-114628bfface" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_01a01620-57c8-7d7a-932a-114628bfface" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentOwnedSales_01a01620-57c8-7105-8b0a-2336467c904d" xlink:href="newt-20260930.xsd#newt_InvestmentOwnedSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_InvestmentOwnedSales_01a01620-57c8-7105-8b0a-2336467c904d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentOwnedSalesYield_01a01620-57c8-70df-8952-95a621e9ff51" xlink:href="newt-20260930.xsd#newt_InvestmentOwnedSalesYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_InvestmentOwnedSalesYield_01a01620-57c8-70df-8952-95a621e9ff51" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage_01a01620-57c8-783a-a484-2e7db64201e5" xlink:href="newt-20260930.xsd#newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage_01a01620-57c8-783a-a484-2e7db64201e5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_01a01620-57c8-7dab-b2e0-e2b47ec28d57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferred_01a01620-57c8-7dab-b2e0-e2b47ec28d57" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NotesSoldValue_01a01620-57c8-784e-b2e7-8d65fede0672" xlink:href="newt-20260930.xsd#newt_NotesSoldValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_NotesSoldValue_01a01620-57c8-784e-b2e7-8d65fede0672" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7997-9cee-614846879e91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCollateralAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7997-9cee-614846879e91" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a01620-57c8-7ced-8b7c-0a7ca41afef2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a01620-57c8-7ced-8b7c-0a7ca41afef2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-77b6-b87a-18915fe7665d" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-77b6-b87a-18915fe7665d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_01a01620-57c8-7fe0-b8bb-5978e35227a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_01a01620-57c8-7fe0-b8bb-5978e35227a7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable_01a01620-57c8-71fb-a63f-3652d1a182a8" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable_01a01620-57c8-71fb-a63f-3652d1a182a8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-72d5-a553-506ea6cc1b82" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-72d5-a553-506ea6cc1b82" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors_01a01620-57c8-78ad-9268-8aa9284e7e84" xlink:href="newt-20260930.xsd#newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors_01a01620-57c8-78ad-9268-8aa9284e7e84" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-763c-ae0a-7dd0dfa25bab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-763c-ae0a-7dd0dfa25bab" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSNarrativeDetails_1" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSNarrativeDetails_1"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSNarrativeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-728e-bbee-8ff2a4488788_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-728e-bbee-8ff2a4488788_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_01a01620-57c8-728e-bbee-8ff2a4488788" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7199-9b13-fe4b28f5bdf0" xlink:href="newt-20260930.xsd#newt_NewtekConventionalLendingLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_01a01620-57c8-7dc6-a73a-86a4ee9c7ab7" xlink:to="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7199-9b13-fe4b28f5bdf0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-57c8-7f99-acda-e69153f6d4d2_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:to="loc_dei_EntityDomain_01a01620-57c8-7f99-acda-e69153f6d4d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_01a01620-57c8-7f99-acda-e69153f6d4d2" xlink:to="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekCommercialLendingMember_01a01620-57c8-7900-8f4d-19c0b2cafe0e" xlink:href="newt-20260930.xsd#newt_NewtekCommercialLendingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_NewtekCommercialLendingMember_01a01620-57c8-7900-8f4d-19c0b2cafe0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-7383-bd4d-9bd6ef626264" xlink:href="newt-20260930.xsd#newt_ConventionalLendingTCPHoldingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-7383-bd4d-9bd6ef626264" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekALPHoldingsMember_01a01620-57c8-77ab-aaed-eeaf72640f57" xlink:href="newt-20260930.xsd#newt_NewtekALPHoldingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-57c8-7bd3-8b0d-face841da83a" xlink:to="loc_newt_NewtekALPHoldingsMember_01a01620-57c8-77ab-aaed-eeaf72640f57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-727d-a173-dc01b10df618_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-727d-a173-dc01b10df618_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryAxis_01a01620-57c8-727d-a173-dc01b10df618" xlink:to="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7054-be58-024639fc84f0" xlink:href="newt-20260930.xsd#newt_NewtekConventionalLendingLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyNonconsolidatedSubsidiaryDomain_01a01620-57c8-7a11-be75-0e0fe5a8313b" xlink:to="loc_newt_NewtekConventionalLendingLLCMember_01a01620-57c8-7054-be58-024639fc84f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7e7f-bed6-b430f12e6f89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7e7f-bed6-b430f12e6f89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7e7f-bed6-b430f12e6f89" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-7025-a578-32e01bd28e51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-77d1-9e96-995c9085e50f" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-7025-a578-32e01bd28e51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-77c6-b0d0-cd354509fa4a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-77c6-b0d0-cd354509fa4a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-77c6-b0d0-cd354509fa4a" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7464-8a96-7ac40e2a9763" xlink:href="newt-20260930.xsd#newt_NewtekTechnologySolutionsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7d5e-98e6-bebc11b98826" xlink:to="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7464-8a96-7ac40e2a9763" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-70e0-ae16-bfb0b20bc708_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-70e0-ae16-bfb0b20bc708_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AssetAcquisitionAxis_01a01620-57c8-70e0-ae16-bfb0b20bc708" xlink:to="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-77dc-9f3e-8597e982fa67" xlink:href="newt-20260930.xsd#newt_ConventionalLendingTCPHoldingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionDomain_01a01620-57c8-7daf-ae78-0c332a92d16e" xlink:to="loc_newt_ConventionalLendingTCPHoldingMember_01a01620-57c8-77dc-9f3e-8597e982fa67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7ee7-8b19-8bea5ed7fd7a" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7e32-815a-dd861843a772_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7e32-815a-dd861843a772_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-57c8-7e32-815a-dd861843a772" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7054-86b6-6eb61e5cde46" xlink:href="newt-20260930.xsd#newt_TSONotesClassANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesClassANotesMember_01a01620-57c8-7054-86b6-6eb61e5cde46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-71e6-8423-9aaf418aac94" xlink:href="newt-20260930.xsd#newt_TSONotesClassBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesClassBNotesMember_01a01620-57c8-71e6-8423-9aaf418aac94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TSONotesMember_01a01620-57c8-765c-8065-22541b39c7f9" xlink:href="newt-20260930.xsd#newt_TSONotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-57c8-7a32-b909-4264c6c07078" xlink:to="loc_newt_TSONotesMember_01a01620-57c8-765c-8065-22541b39c7f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_01a01620-57c8-7d7a-932a-114628bfface" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_01a01620-57c8-7d7a-932a-114628bfface" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentOwnedSales_01a01620-57c8-7105-8b0a-2336467c904d" xlink:href="newt-20260930.xsd#newt_InvestmentOwnedSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_InvestmentOwnedSales_01a01620-57c8-7105-8b0a-2336467c904d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentOwnedSalesYield_01a01620-57c8-70df-8952-95a621e9ff51" xlink:href="newt-20260930.xsd#newt_InvestmentOwnedSalesYield"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_InvestmentOwnedSalesYield_01a01620-57c8-70df-8952-95a621e9ff51" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage_01a01620-57c8-783a-a484-2e7db64201e5" xlink:href="newt-20260930.xsd#newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_AssetAcquisitionAcquiredInterestsInAcquireePercentage_01a01620-57c8-783a-a484-2e7db64201e5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferred_01a01620-57c8-7dab-b2e0-e2b47ec28d57" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetAcquisitionConsiderationTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferred_01a01620-57c8-7dab-b2e0-e2b47ec28d57" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NotesSoldValue_01a01620-57c8-784e-b2e7-8d65fede0672" xlink:href="newt-20260930.xsd#newt_NotesSoldValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_NotesSoldValue_01a01620-57c8-784e-b2e7-8d65fede0672" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7997-9cee-614846879e91" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCollateralAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtInstrumentCollateralAmount_01a01620-57c8-7997-9cee-614846879e91" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a01620-57c8-7ced-8b7c-0a7ca41afef2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DisposalGroupIncludingDiscontinuedOperationConsideration_01a01620-57c8-7ced-8b7c-0a7ca41afef2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-77b6-b87a-18915fe7665d" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-77b6-b87a-18915fe7665d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_01a01620-57c8-7fe0-b8bb-5978e35227a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_ConvertiblePreferredStockSharesIssuedUponConversion_01a01620-57c8-7fe0-b8bb-5978e35227a7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable_01a01620-57c8-71fb-a63f-3652d1a182a8" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationEarnOutReceivable_01a01620-57c8-71fb-a63f-3652d1a182a8" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-72d5-a553-506ea6cc1b82" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-72d5-a553-506ea6cc1b82" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors_01a01620-57c8-78ad-9268-8aa9284e7e84" xlink:href="newt-20260930.xsd#newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_newt_NumberOfAllowedRepresentativesAppointedToBoardOfDirectors_01a01620-57c8-78ad-9268-8aa9284e7e84" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-763c-ae0a-7dd0dfa25bab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7885-8f2d-70505059fdca" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-763c-ae0a-7dd0dfa25bab" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSTransactionwithAffiliatedCompaniesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSTransactionwithAffiliatedCompaniesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSTransactionwithAffiliatedCompaniesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis_01a01620-57c8-7f18-8887-7fc4218f11da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_InvestmentIdentifierAxis_01a01620-57c8-7f18-8887-7fc4218f11da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-74b2-9cf7-27e8dd6f2ede_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-74b2-9cf7-27e8dd6f2ede_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentAffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember_01a01620-57c8-73b4-a707-9bfa344fbe5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember_01a01620-57c8-73b4-a707-9bfa344fbe5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7997-8ed9-d7d33d7123f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7997-8ed9-d7d33d7123f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-75c9-a5b9-15b841532614" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-75c9-a5b9-15b841532614" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7e73-b686-716041c69f58_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7e73-b686-716041c69f58_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7b9a-924c-1b5a9103527d" xlink:href="newt-20260930.xsd#newt_NewtekTechnologySolutionsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:to="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7b9a-924c-1b5a9103527d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7c82-96b0-d0e5fffaa893" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7c82-96b0-d0e5fffaa893" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7d6f-8536-3a09d86b40f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7d6f-8536-3a09d86b40f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-7ae0-aac1-55c3f6eae5df" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-7ae0-aac1-55c3f6eae5df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-57c8-70e5-a6be-91b6b29413af" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-57c8-70e5-a6be-91b6b29413af" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSTransactionwithAffiliatedCompaniesDetails_1" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSTransactionwithAffiliatedCompaniesDetails_1"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSTransactionwithAffiliatedCompaniesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-74b2-9cf7-27e8dd6f2ede_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-74b2-9cf7-27e8dd6f2ede_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-57c8-74b2-9cf7-27e8dd6f2ede" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentAffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-57c8-72d8-a05c-d43fd508e603" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember_01a01620-57c8-73b4-a707-9bfa344fbe5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentAffiliatedIssuerMember_01a01620-57c8-7aff-8b50-c3b0e79bd7c9" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerNoncontrolledMember_01a01620-57c8-73b4-a707-9bfa344fbe5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7997-8ed9-d7d33d7123f6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-7997-8ed9-d7d33d7123f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-57c8-7997-8ed9-d7d33d7123f6" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-75c9-a5b9-15b841532614" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-57c8-74c9-be64-2bf49a87168c" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-57c8-75c9-a5b9-15b841532614" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-79d3-a0b6-bcc2d1f9d9ab" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7e73-b686-716041c69f58_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-7e73-b686-716041c69f58_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-57c8-7e73-b686-716041c69f58" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7b9a-924c-1b5a9103527d" xlink:href="newt-20260930.xsd#newt_NewtekTechnologySolutionsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-57c8-70fa-8f46-5323f7fb54d8" xlink:to="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-57c8-7b9a-924c-1b5a9103527d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7c82-96b0-d0e5fffaa893" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-57c8-7c82-96b0-d0e5fffaa893" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7d6f-8536-3a09d86b40f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_us-gaap_DebtAndEquitySecuritiesUnrealizedGainLoss_01a01620-57c8-7d6f-8536-3a09d86b40f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-7ae0-aac1-55c3f6eae5df" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-57c8-7ae0-aac1-55c3f6eae5df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-57c8-70e5-a6be-91b6b29413af" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7c5d-ba86-d5e562cbfd2d" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-57c8-70e5-a6be-91b6b29413af" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSAvailableforSaleDebtSecuritiesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSAvailableforSaleDebtSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSAvailableforSaleDebtSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7485-a517-c57628a4c48b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b1c-9993-b20b6f8be163" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7485-a517-c57628a4c48b" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b1c-9993-b20b6f8be163" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7cf2-a269-fdc71e20ccd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7b1c-9993-b20b6f8be163" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7cf2-a269-fdc71e20ccd4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7cf2-a269-fdc71e20ccd4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7cf2-a269-fdc71e20ccd4" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7cf2-a269-fdc71e20ccd4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-76b7-acf7-2ba3aabe7076" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7cf2-a269-fdc71e20ccd4" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-76b7-acf7-2ba3aabe7076" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_01a01620-57c8-7920-812a-505d9c8668d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-76b7-acf7-2ba3aabe7076" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_01a01620-57c8-7920-812a-505d9c8668d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7485-a517-c57628a4c48b" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-785c-8f7d-31c26499be89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c8-785c-8f7d-31c26499be89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_01a01620-57c8-78ea-9b8a-d7842d1104ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_01a01620-57c8-78ea-9b8a-d7842d1104ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_01a01620-57c8-7f3b-bec0-ef2ae00dbd51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_01a01620-57c8-7f3b-bec0-ef2ae00dbd51" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_01a01620-57c8-7917-971f-306554c9a028" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract_01a01620-57c8-7a30-a220-1d18903601ec" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_01a01620-57c8-7917-971f-306554c9a028" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSDebtSecuritiesUnrealizedLossesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSDebtSecuritiesUnrealizedLossesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSDebtSecuritiesUnrealizedLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7c62-9a08-0cb1d59a7b48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7c62-9a08-0cb1d59a7b48" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7d67-bca5-1f1763072e9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-7c62-9a08-0cb1d59a7b48" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7d67-bca5-1f1763072e9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7d67-bca5-1f1763072e9e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7d67-bca5-1f1763072e9e" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7d67-bca5-1f1763072e9e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7e88-92a1-caaaf0839ae1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-7d67-bca5-1f1763072e9e" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7e88-92a1-caaaf0839ae1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_01a01620-57c8-76fc-9d48-f30b613a2c37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7e88-92a1-caaaf0839ae1" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_01a01620-57c8-76fc-9d48-f30b613a2c37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_01a01620-57c8-71ee-b122-2d777c1ef703" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_01a01620-57c8-71ee-b122-2d777c1ef703" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_01a01620-57c8-772c-8e9f-f2b4b4d6066d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_01a01620-57c8-772c-8e9f-f2b4b4d6066d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_01a01620-57c8-7503-ae06-639b99b0c7c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_01a01620-57c8-7503-ae06-639b99b0c7c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_01a01620-57c8-7220-bb23-2ba8101e330a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_01a01620-57c8-7220-bb23-2ba8101e330a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_01a01620-57c8-7f14-b0de-31b7204cffbd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_01a01620-57c8-7f14-b0de-31b7204cffbd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_01a01620-57c8-7a94-9fc5-a7ae25db1e1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7124-a095-4fe882b5109e" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_01a01620-57c8-7a94-9fc5-a7ae25db1e1f" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/INVESTMENTSOtherInformationDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#INVESTMENTSOtherInformationDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/INVESTMENTSOtherInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7b05-a653-1729b3b0c7bd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-763b-984f-65e04e425311" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7b05-a653-1729b3b0c7bd" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-763b-984f-65e04e425311" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-700b-b286-dfb348e7801d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_01a01620-57c8-763b-984f-65e04e425311" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-700b-b286-dfb348e7801d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-700b-b286-dfb348e7801d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-700b-b286-dfb348e7801d" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-700b-b286-dfb348e7801d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7022-99d0-648f7bcab5e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-57c8-700b-b286-dfb348e7801d" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7022-99d0-648f7bcab5e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PledgedForDepositsMember_01a01620-57c8-7b93-9b72-306d786614e8" xlink:href="newt-20260930.xsd#newt_PledgedForDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7022-99d0-648f7bcab5e8" xlink:to="loc_newt_PledgedForDepositsMember_01a01620-57c8-7b93-9b72-306d786614e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FRBBorrowingsMember_01a01620-57c8-739d-b711-4cffe7632267" xlink:href="newt-20260930.xsd#newt_FRBBorrowingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7022-99d0-648f7bcab5e8" xlink:to="loc_newt_FRBBorrowingsMember_01a01620-57c8-739d-b711-4cffe7632267" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FHLBBorrowingsMember_01a01620-57c8-7850-b73a-0513b9851024" xlink:href="newt-20260930.xsd#newt_FHLBBorrowingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-57c8-7022-99d0-648f7bcab5e8" xlink:to="loc_newt_FHLBBorrowingsMember_01a01620-57c8-7850-b73a-0513b9851024" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PledgedFinancialInstrumentsNotSeparatelyReportedDebtSecuritiesAvailableForSale_01a01620-57c8-7146-bb93-a3fb33ca138c" xlink:href="newt-20260930.xsd#newt_PledgedFinancialInstrumentsNotSeparatelyReportedDebtSecuritiesAvailableForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_01a01620-57c8-7b05-a653-1729b3b0c7bd" xlink:to="loc_newt_PledgedFinancialInstrumentsNotSeparatelyReportedDebtSecuritiesAvailableForSale_01a01620-57c8-7146-bb93-a3fb33ca138c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSInvestmentPortfolioDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSInvestmentPortfolioDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSInvestmentPortfolioDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7a64-a20d-7a8cb4a6062e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-720a-85c6-fbf048a702b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7a64-a20d-7a8cb4a6062e" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-720a-85c6-fbf048a702b2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_01a01620-57c9-7e03-8741-1d255dacfb61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-720a-85c6-fbf048a702b2" xlink:to="loc_us-gaap_CollateralAxis_01a01620-57c9-7e03-8741-1d255dacfb61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_01a01620-57c9-7e03-8741-1d255dacfb61_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_01a01620-57c9-7e03-8741-1d255dacfb61" xlink:to="loc_us-gaap_CollateralDomain_01a01620-57c9-7e03-8741-1d255dacfb61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_01a01620-57c9-7e03-8741-1d255dacfb61" xlink:to="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CRECollateralMember_01a01620-57c9-7abe-af66-062a0b118d32" xlink:href="newt-20260930.xsd#newt_CRECollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_CRECollateralMember_01a01620-57c9-7abe-af66-062a0b118d32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidentialRealEstateCollateralMember_01a01620-57c9-726b-99fd-e93dcb92e1ed" xlink:href="newt-20260930.xsd#newt_ResidentialRealEstateCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_ResidentialRealEstateCollateralMember_01a01620-57c9-726b-99fd-e93dcb92e1ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_MachineryAndEquipmentCollateralMember_01a01620-57c9-76a7-be07-b01584c1d97f" xlink:href="newt-20260930.xsd#newt_MachineryAndEquipmentCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_MachineryAndEquipmentCollateralMember_01a01620-57c9-76a7-be07-b01584c1d97f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AccountsReceivableAndInventoryCollateralMember_01a01620-57c9-7e66-8bcd-d99d14d6b38a" xlink:href="newt-20260930.xsd#newt_AccountsReceivableAndInventoryCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_AccountsReceivableAndInventoryCollateralMember_01a01620-57c9-7e66-8bcd-d99d14d6b38a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnsecuredCollateralMember_01a01620-57c9-79e1-ba19-52f31863ef2c" xlink:href="newt-20260930.xsd#newt_UnsecuredCollateralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_UnsecuredCollateralMember_01a01620-57c9-79e1-ba19-52f31863ef2c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AllOtherIndustriesMember_01a01620-57c9-7d24-9d69-606be88464d5" xlink:href="newt-20260930.xsd#newt_AllOtherIndustriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7a41-afd6-44c827104943" xlink:to="loc_newt_AllOtherIndustriesMember_01a01620-57c9-7d24-9d69-606be88464d5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-72b7-a775-fa3082d82ed4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-720a-85c6-fbf048a702b2" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-72b7-a775-fa3082d82ed4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-72b7-a775-fa3082d82ed4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-72b7-a775-fa3082d82ed4" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-72b7-a775-fa3082d82ed4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-794d-9e2f-c33309d94d8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-72b7-a775-fa3082d82ed4" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-794d-9e2f-c33309d94d8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-57c9-724e-a432-a13b0e61dea7" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-794d-9e2f-c33309d94d8f" xlink:to="loc_newt_SBA7aLoanMember_01a01620-57c9-724e-a432-a13b0e61dea7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostIndustryLoans_01a01620-57c9-7c78-bee8-c072222c7662" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostIndustryLoans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7a64-a20d-7a8cb4a6062e" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostIndustryLoans_01a01620-57c9-7c78-bee8-c072222c7662" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueIndustryLoans_01a01620-57c9-76de-aafe-803372b108d6" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueIndustryLoans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7a64-a20d-7a8cb4a6062e" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueIndustryLoans_01a01620-57c9-76de-aafe-803372b108d6" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSLoansDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSLoansDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSLoansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70ed-bc3b-38ea3c12603a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-7c6c-8f5e-16cf94eac261" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70ed-bc3b-38ea3c12603a" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-7c6c-8f5e-16cf94eac261" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7d01-a323-602f221ed4d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-7c6c-8f5e-16cf94eac261" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7d01-a323-602f221ed4d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7d01-a323-602f221ed4d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7d01-a323-602f221ed4d7" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7d01-a323-602f221ed4d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7d01-a323-602f221ed4d7" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-57c9-7fc4-b373-a8b126605c1b" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:to="loc_newt_SBA7aLoanMember_01a01620-57c9-7fc4-b373-a8b126605c1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-77da-b6ba-e83f836f7b95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-77da-b6ba-e83f836f7b95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-76a7-a1eb-2cc2a61478e1" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-76a7-a1eb-2cc2a61478e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember_01a01620-57c9-77b2-92b2-21761e4fb9d2" xlink:href="newt-20260930.xsd#newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-757d-9509-ea25d7a33610" xlink:to="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember_01a01620-57c9-77b2-92b2-21761e4fb9d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-717d-b27b-dac159c1aaa0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70ed-bc3b-38ea3c12603a" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-717d-b27b-dac159c1aaa0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees_01a01620-57c9-7e4c-8270-15c8f09db28e" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70ed-bc3b-38ea3c12603a" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees_01a01620-57c9-7e4c-8270-15c8f09db28e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAfterDeferredLoanFees_01a01620-57c9-713e-b11d-da9530926e9b" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossAfterDeferredLoanFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70ed-bc3b-38ea3c12603a" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAfterDeferredLoanFees_01a01620-57c9-713e-b11d-da9530926e9b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSAgingStatusDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSAgingStatusDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSAgingStatusDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-75d1-b1b6-c2d793627051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-75d1-b1b6-c2d793627051" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-74f3-ac49-fe95c56aacd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-75d1-b1b6-c2d793627051" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-74f3-ac49-fe95c56aacd7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-74f3-ac49-fe95c56aacd7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-74f3-ac49-fe95c56aacd7" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-74f3-ac49-fe95c56aacd7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7d06-9758-cfca72bdeff2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-74f3-ac49-fe95c56aacd7" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7d06-9758-cfca72bdeff2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformingFinancingReceivableMember_01a01620-57c9-7475-a356-a22e2896945c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7d06-9758-cfca72bdeff2" xlink:to="loc_us-gaap_PerformingFinancingReceivableMember_01a01620-57c9-7475-a356-a22e2896945c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonperformingFinancingReceivableMember_01a01620-57c9-78c8-970e-c6f54143da18" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonperformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7d06-9758-cfca72bdeff2" xlink:to="loc_us-gaap_NonperformingFinancingReceivableMember_01a01620-57c9-78c8-970e-c6f54143da18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7d4a-a13c-3e853fad53d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-75d1-b1b6-c2d793627051" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7d4a-a13c-3e853fad53d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7d4a-a13c-3e853fad53d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7d4a-a13c-3e853fad53d7" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7d4a-a13c-3e853fad53d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7d4a-a13c-3e853fad53d7" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_01a01620-57c9-7369-8eed-9cd7cacb2a49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:to="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_01a01620-57c9-7369-8eed-9cd7cacb2a49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_01a01620-57c9-76b4-b57d-1da4deb3a268" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:to="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_01a01620-57c9-76b4-b57d-1da4deb3a268" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_01a01620-57c9-73da-90c4-50c02338d3d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:to="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_01a01620-57c9-73da-90c4-50c02338d3d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetPastDueMember_01a01620-57c9-7e8d-9f73-f5e715d02459" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:to="loc_us-gaap_FinancialAssetPastDueMember_01a01620-57c9-7e8d-9f73-f5e715d02459" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetNotPastDueMember_01a01620-57c9-75e4-bbc2-504dcce1c6d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetNotPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-703e-9334-e099e1b3cf9a" xlink:to="loc_us-gaap_FinancialAssetNotPastDueMember_01a01620-57c9-75e4-bbc2-504dcce1c6d5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7b55-a8c2-badebf84e777" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-75d1-b1b6-c2d793627051" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7b55-a8c2-badebf84e777" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7b55-a8c2-badebf84e777_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7b55-a8c2-badebf84e777" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7b55-a8c2-badebf84e777_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7b55-a8c2-badebf84e777" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-7f96-902e-e31df1d1f03e" xlink:href="newt-20260930.xsd#newt_SBA7aLoanLowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:to="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-7f96-902e-e31df1d1f03e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7a93-8ef5-c42b36d8491a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7a93-8ef5-c42b36d8491a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7cdd-803e-21357faa51ef" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7cdd-803e-21357faa51ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember_01a01620-57c9-76d8-b3fc-c9592624fc89" xlink:href="newt-20260930.xsd#newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:to="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansMember_01a01620-57c9-76d8-b3fc-c9592624fc89" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a35f-e91b-710e-a0e9-a0355b1047b0" xlink:href="newt-20260930.xsd#newt_SBAGuaranteedPortionsOfSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-792b-a2a8-afa611f329fa" xlink:to="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a35f-e91b-710e-a0e9-a0355b1047b0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c9-7724-b983-d22fa9e3421e" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-57c9-7724-b983-d22fa9e3421e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-7578-9d80-c7659d6eea47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-7578-9d80-c7659d6eea47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_01a01620-57c9-7acc-b2f2-2c02ebf6ea0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_01a01620-57c9-7acc-b2f2-2c02ebf6ea0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees_01a01620-57c9-79ea-92d3-becc2af07c55" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossDeferredLoanFees_01a01620-57c9-79ea-92d3-becc2af07c55" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c9-7596-9d40-de2e917b0396" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c9-7596-9d40-de2e917b0396" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c9-75ea-8416-22357ebe17dd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7189-a3d6-9bceee00ed0b" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss_01a01620-57c9-75ea-8416-22357ebe17dd" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSCreditQualityIndicatorsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSCreditQualityIndicatorsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSCreditQualityIndicatorsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-78a8-8461-b6e6cf03be34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-78a8-8461-b6e6cf03be34" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78a4-9e56-60e836be1eb3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-78a8-8461-b6e6cf03be34" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78a4-9e56-60e836be1eb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78a4-9e56-60e836be1eb3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78a4-9e56-60e836be1eb3" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78a4-9e56-60e836be1eb3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78a4-9e56-60e836be1eb3" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-57c9-7979-be8a-e8a89dfc7c74" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_SBA7aLoanMember_01a01620-57c9-7979-be8a-e8a89dfc7c74" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansFairValueMember_01a01620-57c9-775b-a8b2-c0a5f22e0718" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansFairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_CommercialAndIndustrialLoansFairValueMember_01a01620-57c9-775b-a8b2-c0a5f22e0718" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-723d-b336-f979961f3e8f" xlink:href="newt-20260930.xsd#newt_SBA7aLoanLowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-723d-b336-f979961f3e8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7600-a997-50cdcf2d29b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7600-a997-50cdcf2d29b8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-739a-a6f7-e2f2a20c9821" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-739a-a6f7-e2f2a20c9821" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansAtFairValueAndCostMember_01a01620-57c9-7eab-a954-ef15344b4a44" xlink:href="newt-20260930.xsd#newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansAtFairValueAndCostMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_CommercialRealEstateCommercialIndustrialAndSBA7aLoansAtFairValueAndCostMember_01a01620-57c9-7eab-a954-ef15344b4a44" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a784-ad56-7898-b18b-5ac299e98d8b" xlink:href="newt-20260930.xsd#newt_SBAGuaranteedPortionsOfSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7a70-a780-a4f0b6b9434e" xlink:to="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a784-ad56-7898-b18b-5ac299e98d8b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_01a01620-57c9-7cdb-bff3-9f767d37fcc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-78a8-8461-b6e6cf03be34" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_01a01620-57c9-7cdb-bff3-9f767d37fcc2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7cdb-bff3-9f767d37fcc2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_01a01620-57c9-7cdb-bff3-9f767d37fcc2" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7cdb-bff3-9f767d37fcc2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_01a01620-57c9-7cdb-bff3-9f767d37fcc2" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RiskGrades14Member_01a01620-57c9-754f-80c4-d91936f9c35d" xlink:href="newt-20260930.xsd#newt_RiskGrades14Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:to="loc_newt_RiskGrades14Member_01a01620-57c9-754f-80c4-d91936f9c35d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RiskGrades56Member_01a01620-57c9-7c33-bad5-2e4df3322fa3" xlink:href="newt-20260930.xsd#newt_RiskGrades56Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:to="loc_newt_RiskGrades56Member_01a01620-57c9-7c33-bad5-2e4df3322fa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RiskGrade7Member_01a01620-57c9-7bfc-86eb-e3d907c7d647" xlink:href="newt-20260930.xsd#newt_RiskGrade7Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:to="loc_newt_RiskGrade7Member_01a01620-57c9-7bfc-86eb-e3d907c7d647" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RiskGrade8Member_01a01620-57c9-7174-af4e-25459aecec5d" xlink:href="newt-20260930.xsd#newt_RiskGrade8Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_01a01620-57c9-7f16-b8bf-62c960a14450" xlink:to="loc_newt_RiskGrade8Member_01a01620-57c9-7174-af4e-25459aecec5d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_01a01620-57c9-762a-869d-aab4f31bb310" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear_01a01620-57c9-762a-869d-aab4f31bb310" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_01a01620-57c9-7ec4-8dc3-60d7d10e87ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear_01a01620-57c9-7ec4-8dc3-60d7d10e87ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_01a01620-57c9-7298-9af6-f5b53fbd2102" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear_01a01620-57c9-7298-9af6-f5b53fbd2102" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_01a01620-57c9-78af-b822-3d14b1f83281" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear_01a01620-57c9-78af-b822-3d14b1f83281" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_01a01620-57c9-7405-8774-0af03cdfbf43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear_01a01620-57c9-7405-8774-0af03cdfbf43" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_01a01620-57c9-763f-8f92-3f0faa4d6e5e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear_01a01620-57c9-763f-8f92-3f0faa4d6e5e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostAndFairValue_01a01620-57c9-7e0a-b769-a91d2580fa66" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostAndFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-7e4b-b6cf-d590c8136262" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossAmortizedCostAndFairValue_01a01620-57c9-7e0a-b769-a91d2580fa66" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSAllowanceforCreditLossDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSAllowanceforCreditLossDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSAllowanceforCreditLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70f6-a926-b0ba6f2bd228" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-793b-b051-bed537c311d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70f6-a926-b0ba6f2bd228" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-793b-b051-bed537c311d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7e61-adde-86e82fcb46e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-793b-b051-bed537c311d3" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7e61-adde-86e82fcb46e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7e61-adde-86e82fcb46e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7e61-adde-86e82fcb46e0" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7e61-adde-86e82fcb46e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7f07-8d11-9dadd1f281af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7e61-adde-86e82fcb46e0" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7f07-8d11-9dadd1f281af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-74fc-857d-7ad34cb84dcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7f07-8d11-9dadd1f281af" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-74fc-857d-7ad34cb84dcc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7f9c-924d-3034bfaa58d8" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7f07-8d11-9dadd1f281af" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7f9c-924d-3034bfaa58d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-57c9-7e79-9ea7-3790c4911c23" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7f07-8d11-9dadd1f281af" xlink:to="loc_newt_SBA7aLoanMember_01a01620-57c9-7e79-9ea7-3790c4911c23" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70f6-a926-b0ba6f2bd228" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c9-77a1-843f-34eaa60edc7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c9-77a1-843f-34eaa60edc7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_01a01620-57c9-7b3f-a861-576a15a527d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff_01a01620-57c9-7b3f-a861-576a15a527d3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_01a01620-57c9-7381-af72-737b678254ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery_01a01620-57c9-7381-af72-737b678254ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableCreditLossExpenseReversalExcludingUnfundedCommitments_01a01620-57c9-7fdb-9528-3eacedd64015" xlink:href="newt-20260930.xsd#newt_FinancingReceivableCreditLossExpenseReversalExcludingUnfundedCommitments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_01a01620-57c9-7eb3-90db-ea39549039a1" xlink:to="loc_newt_FinancingReceivableCreditLossExpenseReversalExcludingUnfundedCommitments_01a01620-57c9-7fdb-9528-3eacedd64015" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest_01a01620-57c9-7351-8af3-fa65cc3fcb37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableCreditLossExpenseReversalUnfundedCommitments_01a01620-57c9-70f7-addf-74b4566ab2f6" xlink:href="newt-20260930.xsd#newt_FinancingReceivableCreditLossExpenseReversalUnfundedCommitments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-70f6-a926-b0ba6f2bd228" xlink:to="loc_newt_FinancingReceivableCreditLossExpenseReversalUnfundedCommitments_01a01620-57c9-70f7-addf-74b4566ab2f6" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSNonaccrualLoansDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSNonaccrualLoansDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSNonaccrualLoansDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-702b-b990-622421f3c685" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-71fb-b00f-39d3fb583d95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-702b-b990-622421f3c685" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-71fb-b00f-39d3fb583d95" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78fd-a04e-56eefa6e344a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-71fb-b00f-39d3fb583d95" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78fd-a04e-56eefa6e344a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78fd-a04e-56eefa6e344a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78fd-a04e-56eefa6e344a" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78fd-a04e-56eefa6e344a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78fd-a04e-56eefa6e344a" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-7e50-aba8-87c3da98041c" xlink:href="newt-20260930.xsd#newt_SBA7aLoanLowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:to="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-7e50-aba8-87c3da98041c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7097-bd57-a880a50504f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-7097-bd57-a880a50504f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7adf-819d-462d211c9c98" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7adf-819d-462d211c9c98" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a785-8736-7ccf-94ba-015cda375a72" xlink:href="newt-20260930.xsd#newt_SBAGuaranteedPortionsOfSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7be3-8308-1676432975e9" xlink:to="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a785-8736-7ccf-94ba-015cda375a72" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance_01a01620-57c9-78f5-b598-e89267a8237c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-702b-b990-622421f3c685" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrualNoAllowance_01a01620-57c9-78f5-b598-e89267a8237c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_01a01620-57c9-71ce-afb7-b42615cec7ad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-702b-b990-622421f3c685" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestNonaccrual_01a01620-57c9-71ce-afb7-b42615cec7ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance_01a01620-57c9-7e28-9716-ee7c4bfd5036" xlink:href="newt-20260930.xsd#newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-702b-b990-622421f3c685" xlink:to="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance_01a01620-57c9-7e28-9716-ee7c4bfd5036" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSIndividuallyAssessedDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSIndividuallyAssessedDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSIndividuallyAssessedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74e5-b6b8-bf1d1de59b23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-74ee-89cb-24c7d7b0c88c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74e5-b6b8-bf1d1de59b23" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-74ee-89cb-24c7d7b0c88c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_01a01620-57c9-77a6-a63e-8aeb0963c625" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-74ee-89cb-24c7d7b0c88c" xlink:to="loc_us-gaap_CollateralAxis_01a01620-57c9-77a6-a63e-8aeb0963c625" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_01a01620-57c9-77a6-a63e-8aeb0963c625_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_01a01620-57c9-77a6-a63e-8aeb0963c625" xlink:to="loc_us-gaap_CollateralDomain_01a01620-57c9-77a6-a63e-8aeb0963c625_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_01a01620-57c9-7d78-b2c4-91ac10826d50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_01a01620-57c9-77a6-a63e-8aeb0963c625" xlink:to="loc_us-gaap_CollateralDomain_01a01620-57c9-7d78-b2c4-91ac10826d50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealEstateMember_01a01620-57c9-7798-adbc-e01e9ecab051" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7d78-b2c4-91ac10826d50" xlink:to="loc_us-gaap_RealEstateMember_01a01620-57c9-7798-adbc-e01e9ecab051" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UncollateralizedMember_01a01620-57c9-7e12-aef8-319281fddf8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UncollateralizedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_01a01620-57c9-7d78-b2c4-91ac10826d50" xlink:to="loc_us-gaap_UncollateralizedMember_01a01620-57c9-7e12-aef8-319281fddf8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7142-98a4-9257ff58c60c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-74ee-89cb-24c7d7b0c88c" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7142-98a4-9257ff58c60c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7142-98a4-9257ff58c60c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7142-98a4-9257ff58c60c" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7142-98a4-9257ff58c60c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7142-98a4-9257ff58c60c" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-78c6-af12-3da8aeea5bed" xlink:href="newt-20260930.xsd#newt_SBA7aLoanLowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:to="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-78c6-af12-3da8aeea5bed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-70d1-b95e-c67906a2aa4a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-70d1-b95e-c67906a2aa4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7450-8982-238315b44ab9" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7450-8982-238315b44ab9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a785-deb6-72c6-b02d-5a5f152a32c3" xlink:href="newt-20260930.xsd#newt_SBAGuaranteedPortionsOfSBA7aLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-745f-a95f-ef244a8591b5" xlink:to="loc_newt_SBAGuaranteedPortionsOfSBA7aLoansMember_01a1a785-deb6-72c6-b02d-5a5f152a32c3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossUnpaidPrincipalBalance_01a01620-57c9-70c8-979a-2850d7ac8fdd" xlink:href="newt-20260930.xsd#newt_FinancingReceivableIndividuallyEvaluatedForCreditLossUnpaidPrincipalBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74e5-b6b8-bf1d1de59b23" xlink:to="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossUnpaidPrincipalBalance_01a01620-57c9-70c8-979a-2850d7ac8fdd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance_01a01620-57c9-732b-b44d-12802ddec3d8" xlink:href="newt-20260930.xsd#newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74e5-b6b8-bf1d1de59b23" xlink:to="loc_newt_FinancingReceivableIndividuallyEvaluatedForCreditLossRelatedAllowance_01a01620-57c9-732b-b44d-12802ddec3d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-728f-bf28-37af5f6bfa75" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74e5-b6b8-bf1d1de59b23" xlink:to="loc_us-gaap_FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss_01a01620-57c9-728f-bf28-37af5f6bfa75" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSLoanModificationsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSLoanModificationsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSLoanModificationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-723c-ad0d-2362bae5e109" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-73a4-8139-cb5b21beccba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-723c-ad0d-2362bae5e109" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-73a4-8139-cb5b21beccba" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationAxis_01a01620-57c9-7db0-8dc7-220e99e89acb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoanRestructuringModificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-73a4-8139-cb5b21beccba" xlink:to="loc_us-gaap_LoanRestructuringModificationAxis_01a01620-57c9-7db0-8dc7-220e99e89acb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-7db0-8dc7-220e99e89acb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_01a01620-57c9-7db0-8dc7-220e99e89acb" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-7db0-8dc7-220e99e89acb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoanRestructuringModificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LoanRestructuringModificationAxis_01a01620-57c9-7db0-8dc7-220e99e89acb" xlink:to="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentDelayMember_01a01620-57c9-781f-bda4-b710bca77abc" xlink:href="newt-20260930.xsd#newt_PaymentDelayMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:to="loc_newt_PaymentDelayMember_01a01620-57c9-781f-bda4-b710bca77abc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ExtendedMaturityAndPaymentDeferralMember_01a01620-57c9-7f55-87f4-4a5b4a2bb4ad" xlink:href="newt-20260930.xsd#newt_ExtendedMaturityAndPaymentDeferralMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:to="loc_newt_ExtendedMaturityAndPaymentDeferralMember_01a01620-57c9-7f55-87f4-4a5b4a2bb4ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtendedMaturityAndPrincipalForgivenessMember_01a01620-57c9-778b-80c0-9f1a4adedc45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExtendedMaturityAndPrincipalForgivenessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:to="loc_us-gaap_ExtendedMaturityAndPrincipalForgivenessMember_01a01620-57c9-778b-80c0-9f1a4adedc45" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentDelayAndPrincipalForgivenessMember_01a1a788-247d-7bca-9275-4a8a7d9398ca" xlink:href="newt-20260930.xsd#newt_PaymentDelayAndPrincipalForgivenessMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LoanRestructuringModificationDomain_01a01620-57c9-792c-bb6c-2dec25f226d7" xlink:to="loc_newt_PaymentDelayAndPrincipalForgivenessMember_01a1a788-247d-7bca-9275-4a8a7d9398ca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78b0-bb84-fe270e0dc043" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-73a4-8139-cb5b21beccba" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78b0-bb84-fe270e0dc043" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78b0-bb84-fe270e0dc043_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78b0-bb84-fe270e0dc043" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-78b0-bb84-fe270e0dc043_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7876-95df-8ac521cbc98f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-78b0-bb84-fe270e0dc043" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7876-95df-8ac521cbc98f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-73f6-8268-852e6659cf71" xlink:href="newt-20260930.xsd#newt_SBA7aLoanLowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7876-95df-8ac521cbc98f" xlink:to="loc_newt_SBA7aLoanLowerOfCostOrMarketMember_01a01620-57c9-73f6-8268-852e6659cf71" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-79f9-be1d-974e6580b40f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialRealEstateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7876-95df-8ac521cbc98f" xlink:to="loc_us-gaap_CommercialRealEstateMember_01a01620-57c9-79f9-be1d-974e6580b40f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-746d-886c-cbbd0d576076" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7876-95df-8ac521cbc98f" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-746d-886c-cbbd0d576076" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod_01a01620-57c9-79fd-b7f6-58e344b6cf76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-723c-ad0d-2362bae5e109" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestModifiedPeriod_01a01620-57c9-79fd-b7f6-58e344b6cf76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent_01a01620-57c9-72ad-9d5d-1e35a584880e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-723c-ad0d-2362bae5e109" xlink:to="loc_us-gaap_FinancingReceivableModificationToTotalFinancingReceivablesExcludingAccruedInterestPercent_01a01620-57c9-72ad-9d5d-1e35a584880e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/LOANSHeldforSaleDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#LOANSHeldforSaleDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/LOANSHeldforSaleDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74c8-a0d5-0b646eea2133" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-746d-8473-2a7b75e5da93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74c8-a0d5-0b646eea2133" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-746d-8473-2a7b75e5da93" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7ef3-802b-ea586181bcea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-746d-8473-2a7b75e5da93" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7ef3-802b-ea586181bcea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7ef3-802b-ea586181bcea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7ef3-802b-ea586181bcea" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7ef3-802b-ea586181bcea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_01a01620-57c9-7ef3-802b-ea586181bcea" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FirstLienMember_01a01620-57c9-780a-b418-00603b4191e0" xlink:href="newt-20260930.xsd#newt_FirstLienMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:to="loc_newt_FirstLienMember_01a01620-57c9-780a-b418-00603b4191e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecondLienMember_01a01620-57c9-7903-be98-d7891b8c01c2" xlink:href="newt-20260930.xsd#newt_SecondLienMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:to="loc_newt_SecondLienMember_01a01620-57c9-7903-be98-d7891b8c01c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-57c9-702f-9e19-8b508b650533" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:to="loc_newt_SBA7aLoanMember_01a01620-57c9-702f-9e19-8b508b650533" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7113-89a6-c7cc82a7f239" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-57c9-7113-89a6-c7cc82a7f239" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ALPLoansMember_01a01620-57c9-72d0-929f-455e7f9c4a8d" xlink:href="newt-20260930.xsd#newt_ALPLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_01a01620-57c9-7071-8876-aa17bc5c6683" xlink:to="loc_newt_ALPLoansMember_01a01620-57c9-72d0-929f-455e7f9c4a8d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-76e1-b970-8371a0be3ebc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-746d-8473-2a7b75e5da93" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-76e1-b970-8371a0be3ebc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-76e1-b970-8371a0be3ebc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-76e1-b970-8371a0be3ebc" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-76e1-b970-8371a0be3ebc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7f69-87d5-b626450e6134" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_01a01620-57c9-76e1-b970-8371a0be3ebc" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7f69-87d5-b626450e6134" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformingFinancingReceivableMember_01a01620-57c9-7db8-bee2-d098e1b66328" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7f69-87d5-b626450e6134" xlink:to="loc_us-gaap_PerformingFinancingReceivableMember_01a01620-57c9-7db8-bee2-d098e1b66328" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonperformingFinancingReceivableMember_01a01620-57c9-779e-b008-d78697a92ec7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonperformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_01a01620-57c9-7f69-87d5-b626450e6134" xlink:to="loc_us-gaap_NonperformingFinancingReceivableMember_01a01620-57c9-779e-b008-d78697a92ec7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7a97-b917-1794edccc4db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_01a01620-57c9-746d-8473-2a7b75e5da93" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7a97-b917-1794edccc4db" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7a97-b917-1794edccc4db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7a97-b917-1794edccc4db" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7a97-b917-1794edccc4db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_01a01620-57c9-7a97-b917-1794edccc4db" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_01a01620-57c9-7dfc-b52d-b667172708e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables30To59DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:to="loc_us-gaap_FinancingReceivables30To59DaysPastDueMember_01a01620-57c9-7dfc-b52d-b667172708e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_01a01620-57c9-74d1-b537-d46d20620247" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivables60To89DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:to="loc_us-gaap_FinancingReceivables60To89DaysPastDueMember_01a01620-57c9-74d1-b537-d46d20620247" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_01a01620-57c9-7e82-b666-d270c6cf86c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:to="loc_us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember_01a01620-57c9-7e82-b666-d270c6cf86c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetPastDueMember_01a01620-57c9-742e-8010-946a3aae1a83" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:to="loc_us-gaap_FinancialAssetPastDueMember_01a01620-57c9-742e-8010-946a3aae1a83" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetNotPastDueMember_01a01620-57c9-7162-ac8a-9ffb0418149f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetNotPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_01a01620-57c9-7258-a0a2-ddeb69f88f6d" xlink:to="loc_us-gaap_FinancialAssetNotPastDueMember_01a01620-57c9-7162-ac8a-9ffb0418149f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableAtFairValueAbstract_01a01620-57c9-7c52-8e19-e26f2aaf570e" xlink:href="newt-20260930.xsd#newt_FinancingReceivableAtFairValueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74c8-a0d5-0b646eea2133" xlink:to="loc_newt_FinancingReceivableAtFairValueAbstract_01a01620-57c9-7c52-8e19-e26f2aaf570e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleBeforeDeferredFeesAndCosts_01a01620-57c9-7df1-88f1-e48e147b853a" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleBeforeDeferredFeesAndCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_FinancingReceivableAtFairValueAbstract_01a01620-57c9-7c52-8e19-e26f2aaf570e" xlink:to="loc_newt_FinancingReceivableHeldForSaleBeforeDeferredFeesAndCosts_01a01620-57c9-7df1-88f1-e48e147b853a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-57c9-7565-9014-e32947991415" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_FinancingReceivableAtFairValueAbstract_01a01620-57c9-7c52-8e19-e26f2aaf570e" xlink:to="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-57c9-7565-9014-e32947991415" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-57c9-7104-85e7-ae139af6711a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansReceivableHeldForSaleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_FinancingReceivableAtFairValueAbstract_01a01620-57c9-7c52-8e19-e26f2aaf570e" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-57c9-7104-85e7-ae139af6711a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableAtLowerOfCostOrMarketAbstract_01a01620-57c9-7313-9abe-e1950fdb4c2a" xlink:href="newt-20260930.xsd#newt_FinancingReceivableAtLowerOfCostOrMarketAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_01a01620-57c9-74c8-a0d5-0b646eea2133" xlink:to="loc_newt_FinancingReceivableAtLowerOfCostOrMarketAbstract_01a01620-57c9-7313-9abe-e1950fdb4c2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketBeforeDeferredFeesAndCosts_01a01620-57c9-77f9-8d99-e4a8976ed752" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketBeforeDeferredFeesAndCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_FinancingReceivableAtLowerOfCostOrMarketAbstract_01a01620-57c9-7313-9abe-e1950fdb4c2a" xlink:to="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketBeforeDeferredFeesAndCosts_01a01620-57c9-77f9-8d99-e4a8976ed752" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-57c9-7052-8dcf-86dad74c2145" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_FinancingReceivableAtLowerOfCostOrMarketAbstract_01a01620-57c9-7313-9abe-e1950fdb4c2a" xlink:to="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-57c9-7052-8dcf-86dad74c2145" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSInvestmentswithAffiliatesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSInvestmentswithAffiliatesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSInvestmentswithAffiliatesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7f81-91db-44e55c408448" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-73c0-b60f-bcab9336551b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7f81-91db-44e55c408448" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-73c0-b60f-bcab9336551b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-786b-adcb-983b24ed9fa8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-73c0-b60f-bcab9336551b" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-786b-adcb-983b24ed9fa8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-786b-adcb-983b24ed9fa8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-786b-adcb-983b24ed9fa8" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-786b-adcb-983b24ed9fa8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-71de-8b1a-866b066e0828" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-786b-adcb-983b24ed9fa8" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-71de-8b1a-866b066e0828" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_01a01620-5860-710d-b7ac-d5485649d8dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_01a01620-5860-71de-8b1a-866b066e0828" xlink:to="loc_us-gaap_RelatedPartyMember_01a01620-5860-710d-b7ac-d5485649d8dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherReceivables_01a01620-5860-78d7-8fac-7851dd8f333b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7f81-91db-44e55c408448" xlink:to="loc_us-gaap_OtherReceivables_01a01620-5860-78d7-8fac-7851dd8f333b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_OtherReceivablesLiabilitiesNet_01a01620-5860-7866-b5fc-9164e91fe557" xlink:href="newt-20260930.xsd#newt_OtherReceivablesLiabilitiesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7f81-91db-44e55c408448" xlink:to="loc_newt_OtherReceivablesLiabilitiesNet_01a01620-5860-7866-b5fc-9164e91fe557" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSTransactionswithJointVenturesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSTransactionswithJointVenturesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSTransactionswithJointVenturesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7266-bf7e-be74e6a9e1bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7266-bf7e-be74e6a9e1bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5860-7d2a-85cd-bc21797f4a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7266-bf7e-be74e6a9e1bc" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5860-7d2a-85cd-bc21797f4a7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5860-7d2a-85cd-bc21797f4a7f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5860-7d2a-85cd-bc21797f4a7f" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5860-7d2a-85cd-bc21797f4a7f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5860-7d73-a7d7-a0888782f89f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5860-7d2a-85cd-bc21797f4a7f" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5860-7d73-a7d7-a0888782f89f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherControlledCompaniesMember_01a01620-5860-7863-a39a-10b7942d9d12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherControlledCompaniesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5860-7d73-a7d7-a0888782f89f" xlink:to="loc_us-gaap_OtherControlledCompaniesMember_01a01620-5860-7863-a39a-10b7942d9d12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7c0c-bb48-d813ecaf1ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7266-bf7e-be74e6a9e1bc" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7c0c-bb48-d813ecaf1ea8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7c0c-bb48-d813ecaf1ea8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7c0c-bb48-d813ecaf1ea8" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7c0c-bb48-d813ecaf1ea8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7bb3-ba97-e4a8f11a39e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7c0c-bb48-d813ecaf1ea8" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7bb3-ba97-e4a8f11a39e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_01a01620-5860-773b-a4c8-73d08266bae1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7bb3-ba97-e4a8f11a39e8" xlink:to="loc_us-gaap_RelatedPartyMember_01a01620-5860-773b-a4c8-73d08266bae1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-5860-70cf-9fc0-0288557a8be5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-5860-70cf-9fc0-0288557a8be5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeDividend_01a01620-5860-719b-8246-8897c865db0f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIncomeDividend"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_InvestmentIncomeDividend_01a01620-5860-719b-8246-8897c865db0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_01a01620-5860-701c-9021-d87c3e6ab9bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_NoninterestIncome_01a01620-5860-701c-9021-d87c3e6ab9bb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestExpense_01a01620-5860-7fbf-9203-4f98f22d55d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_NoninterestExpense_01a01620-5860-7fbf-9203-4f98f22d55d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossAttributableToParent_01a01620-5860-7ed2-8a75-8a6fa8579048" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-774e-8736-a5b7cfd0323e" xlink:to="loc_us-gaap_IncomeLossAttributableToParent_01a01620-5860-7ed2-8a75-8a6fa8579048" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSBankDepositsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSBankDepositsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/TRANSACTIONSWITHAFFILIATEDCOMPANIESANDRELATEDPARTYTRANSACTIONSBankDepositsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7d60-add3-a8ab5e7e70e7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7450-b60d-1b8aa2d8647d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7d60-add3-a8ab5e7e70e7" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7450-b60d-1b8aa2d8647d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7b5d-a6c4-96c7253556a9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_01a01620-5860-7450-b60d-1b8aa2d8647d" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7b5d-a6c4-96c7253556a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7b5d-a6c4-96c7253556a9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7b5d-a6c4-96c7253556a9" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7b5d-a6c4-96c7253556a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7960-b1a7-0a1ddd03fd43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_01a01620-5860-7b5d-a6c4-96c7253556a9" xlink:to="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7960-b1a7-0a1ddd03fd43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_OfficersAndDirectorsMember_01a01620-5860-74d4-afe3-bdb4f2e493ff" xlink:href="newt-20260930.xsd#newt_OfficersAndDirectorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_01a01620-5860-7960-b1a7-0a1ddd03fd43" xlink:to="loc_newt_OfficersAndDirectorsMember_01a01620-5860-74d4-afe3-bdb4f2e493ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FederalDepositInsuranceCorporationInsuredDeposits_01a01620-5860-7ece-a2a3-d906b8deeaff" xlink:href="newt-20260930.xsd#newt_FederalDepositInsuranceCorporationInsuredDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7d60-add3-a8ab5e7e70e7" xlink:to="loc_newt_FederalDepositInsuranceCorporationInsuredDeposits_01a01620-5860-7ece-a2a3-d906b8deeaff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NonFederalDepositInsuranceCorporationInsuredDeposits_01a01620-5860-7ea1-be4d-9567a364a9a1" xlink:href="newt-20260930.xsd#newt_NonFederalDepositInsuranceCorporationInsuredDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7d60-add3-a8ab5e7e70e7" xlink:to="loc_newt_NonFederalDepositInsuranceCorporationInsuredDeposits_01a01620-5860-7ea1-be4d-9567a364a9a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_01a01620-5860-7f2d-aa71-f8c97bbe2403" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_01a01620-5860-7d60-add3-a8ab5e7e70e7" xlink:to="loc_us-gaap_Deposits_01a01620-5860-7f2d-aa71-f8c97bbe2403" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SERVICINGASSETSLoansServicedDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SERVICINGASSETSLoansServicedDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SERVICINGASSETSLoansServicedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-752f-9b23-073a555de368" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7b24-82dc-5025214d70c9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-752f-9b23-073a555de368" xlink:to="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7b24-82dc-5025214d70c9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7ba4-9ca6-07db7bbf832c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7b24-82dc-5025214d70c9" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7ba4-9ca6-07db7bbf832c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7ba4-9ca6-07db7bbf832c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7ba4-9ca6-07db7bbf832c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7ba4-9ca6-07db7bbf832c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7745-b2c7-96343e20b9ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7ba4-9ca6-07db7bbf832c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7745-b2c7-96343e20b9ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-5861-7531-9ef5-f62ac94a46fb" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7745-b2c7-96343e20b9ea" xlink:to="loc_newt_SBA7aLoanMember_01a01620-5861-7531-9ef5-f62ac94a46fb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ALPLoansMember_01a01620-5861-7400-854f-b6485bdcd9c0" xlink:href="newt-20260930.xsd#newt_ALPLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7745-b2c7-96343e20b9ea" xlink:to="loc_newt_ALPLoansMember_01a01620-5861-7400-854f-b6485bdcd9c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A504LoanMember_01a01620-5861-7a92-9e6a-d40a3c3fa34d" xlink:href="newt-20260930.xsd#newt_A504LoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7745-b2c7-96343e20b9ea" xlink:to="loc_newt_A504LoanMember_01a01620-5861-7a92-9e6a-d40a3c3fa34d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ServicingAssetLoansServiced_01a01620-5861-7691-8da1-f180750d0b3a" xlink:href="newt-20260930.xsd#newt_ServicingAssetLoansServiced"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-752f-9b23-073a555de368" xlink:to="loc_newt_ServicingAssetLoansServiced_01a01620-5861-7691-8da1-f180750d0b3a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SERVICINGASSETSFairValueandValuationAssumptionsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SERVICINGASSETSFairValueandValuationAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SERVICINGASSETSFairValueandValuationAssumptionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7633-8af2-388e48ed55d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7cd3-8914-77ea44db0a9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7633-8af2-388e48ed55d4" xlink:to="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7cd3-8914-77ea44db0a9b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a01620-5861-7f31-981d-17b37c8bfc09" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7cd3-8914-77ea44db0a9b" xlink:to="loc_srt_RangeAxis_01a01620-5861-7f31-981d-17b37c8bfc09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5861-7f31-981d-17b37c8bfc09_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_01a01620-5861-7f31-981d-17b37c8bfc09" xlink:to="loc_srt_RangeMember_01a01620-5861-7f31-981d-17b37c8bfc09_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5861-7165-a67c-fc790a90cc6f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_01a01620-5861-7f31-981d-17b37c8bfc09" xlink:to="loc_srt_RangeMember_01a01620-5861-7165-a67c-fc790a90cc6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_01a01620-5861-7eda-92bc-1c0796b42bde" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-7165-a67c-fc790a90cc6f" xlink:to="loc_srt_WeightedAverageMember_01a01620-5861-7eda-92bc-1c0796b42bde" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a01620-5861-7ecd-949a-e59ab73ee8dc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-7165-a67c-fc790a90cc6f" xlink:to="loc_srt_MinimumMember_01a01620-5861-7ecd-949a-e59ab73ee8dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a01620-5861-76ed-825b-16286f74707a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-7165-a67c-fc790a90cc6f" xlink:to="loc_srt_MaximumMember_01a01620-5861-76ed-825b-16286f74707a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7818-960e-edd64b3dd7e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7cd3-8914-77ea44db0a9b" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7818-960e-edd64b3dd7e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7818-960e-edd64b3dd7e3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7818-960e-edd64b3dd7e3" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7818-960e-edd64b3dd7e3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-76dc-808e-e88baabbd113" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7818-960e-edd64b3dd7e3" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-76dc-808e-e88baabbd113" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_01a01620-5861-7a7d-8c45-862dab764d3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-76dc-808e-e88baabbd113" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_01a01620-5861-7a7d-8c45-862dab764d3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPrepaymentRateMember_01a01620-5861-7c37-b1fe-e27a94d6f942" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputPrepaymentRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-76dc-808e-e88baabbd113" xlink:to="loc_us-gaap_MeasurementInputPrepaymentRateMember_01a01620-5861-7c37-b1fe-e27a94d6f942" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDefaultRateMember_01a01620-5861-772a-816f-8cb6409ed482" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputDefaultRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-76dc-808e-e88baabbd113" xlink:to="loc_us-gaap_MeasurementInputDefaultRateMember_01a01620-5861-772a-816f-8cb6409ed482" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_01a01620-5861-70a6-ac09-8e3f5bb45831" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7cd3-8914-77ea44db0a9b" xlink:to="loc_us-gaap_ValuationTechniqueAxis_01a01620-5861-70a6-ac09-8e3f5bb45831" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-70a6-ac09-8e3f5bb45831_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_01a01620-5861-70a6-ac09-8e3f5bb45831" xlink:to="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-70a6-ac09-8e3f5bb45831_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-702a-b14a-ba23aad8d5ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_01a01620-5861-70a6-ac09-8e3f5bb45831" xlink:to="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-702a-b14a-ba23aad8d5ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FairValueMember_01a01620-5861-7de4-b65e-f979151f2956" xlink:href="newt-20260930.xsd#newt_FairValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-702a-b14a-ba23aad8d5ec" xlink:to="loc_newt_FairValueMember_01a01620-5861-7de4-b65e-f979151f2956" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LowerOfCostOrMarketMember_01a01620-5861-7040-b4c4-8b9148cd7632" xlink:href="newt-20260930.xsd#newt_LowerOfCostOrMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_01a01620-5861-702a-b14a-ba23aad8d5ec" xlink:to="loc_newt_LowerOfCostOrMarketMember_01a01620-5861-7040-b4c4-8b9148cd7632" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAsset_01a01620-5861-7f1e-98d3-02afc6ffa4d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7633-8af2-388e48ed55d4" xlink:to="loc_us-gaap_ServicingAsset_01a01620-5861-7f1e-98d3-02afc6ffa4d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetMeasurementInput_01a01620-5861-76ab-b73c-f0f74bd34fef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7633-8af2-388e48ed55d4" xlink:to="loc_us-gaap_ServicingAssetMeasurementInput_01a01620-5861-76ab-b73c-f0f74bd34fef" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SERVICINGASSETSServicingFeeIncomeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SERVICINGASSETSServicingFeeIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SERVICINGASSETSServicingFeeIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7e9f-addc-f8ff02981124" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7e1d-b3b0-34f6af8f1c10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetsAtFairValueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7e9f-addc-f8ff02981124" xlink:to="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7e1d-b3b0-34f6af8f1c10" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-7100-951e-7add220d662f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueTable_01a01620-5861-7e1d-b3b0-34f6af8f1c10" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-7100-951e-7add220d662f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7100-951e-7add220d662f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-7100-951e-7add220d662f" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7100-951e-7add220d662f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7492-9ea7-25a8e128ae40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-7100-951e-7add220d662f" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7492-9ea7-25a8e128ae40" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_01a01620-5861-7dd5-bdba-02b688f7a43f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentUnaffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7492-9ea7-25a8e128ae40" xlink:to="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_01a01620-5861-7dd5-bdba-02b688f7a43f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-5861-7cf1-8920-574f810e15db" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ServicingAssetsAtFairValueLineItems_01a01620-5861-7e9f-addc-f8ff02981124" xlink:to="loc_us-gaap_ContractuallySpecifiedServicingFeesLateFeesAndAncillaryFeesEarnedInExchangeForServicingFinancialAssets_01a01620-5861-7cf1-8920-574f810e15db" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSGoodwillDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#GOODWILLANDINTANGIBLEASSETSGoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_01a01620-5861-76cc-8d9a-66ee7684851d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-746e-8978-70971fe66f23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_01a01620-5861-76cc-8d9a-66ee7684851d" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-746e-8978-70971fe66f23" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7c52-b722-f0313bbd3cae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-746e-8978-70971fe66f23" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7c52-b722-f0313bbd3cae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5861-7c52-b722-f0313bbd3cae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7c52-b722-f0313bbd3cae" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5861-7c52-b722-f0313bbd3cae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5861-7f00-8287-b78662b80fba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7c52-b722-f0313bbd3cae" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5861-7f00-8287-b78662b80fba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_BankingSegmentMember_01a01620-5861-7b22-b536-b4437bad99f2" xlink:href="newt-20260930.xsd#newt_BankingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5861-7f00-8287-b78662b80fba" xlink:to="loc_newt_BankingSegmentMember_01a01620-5861-7b22-b536-b4437bad99f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsMember_01a01620-5861-783f-bfff-b23db3f50286" xlink:href="newt-20260930.xsd#newt_PaymentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5861-7f00-8287-b78662b80fba" xlink:to="loc_newt_PaymentsMember_01a01620-5861-783f-bfff-b23db3f50286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_01a01620-5861-7d19-b21b-26d8eac54f0c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a01620-5861-76cc-8d9a-66ee7684851d" xlink:to="loc_us-gaap_Goodwill_01a01620-5861-7d19-b21b-26d8eac54f0c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSIntangibleAssetsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#GOODWILLANDINTANGIBLEASSETSIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7306-8dd4-b2beb62d38a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-7a36-9708-521f6a47a24e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7306-8dd4-b2beb62d38a1" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-7a36-9708-521f6a47a24e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-76f9-839d-1eaad8f4d7a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-7a36-9708-521f6a47a24e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-76f9-839d-1eaad8f4d7a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-76f9-839d-1eaad8f4d7a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-76f9-839d-1eaad8f4d7a1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-76f9-839d-1eaad8f4d7a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-79c1-ad23-6f3851a5c221" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-76f9-839d-1eaad8f4d7a1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-79c1-ad23-6f3851a5c221" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CoreDepositsMember_01a01620-5861-72fa-a4cd-d5b83d38404c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CoreDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-79c1-ad23-6f3851a5c221" xlink:to="loc_us-gaap_CoreDepositsMember_01a01620-5861-72fa-a4cd-d5b83d38404c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a01620-5861-7fed-930e-1ea41b9a0cbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7306-8dd4-b2beb62d38a1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_01a01620-5861-7fed-930e-1ea41b9a0cbc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a01620-5861-7d66-be06-0de3f030acad" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7306-8dd4-b2beb62d38a1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_01a01620-5861-7d66-be06-0de3f030acad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a01620-5861-7191-830c-e625ad18d357" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7306-8dd4-b2beb62d38a1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_01a01620-5861-7191-830c-e625ad18d357" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#GOODWILLANDINTANGIBLEASSETSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_01a01620-5861-7c9f-8937-95a8c4aef522" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-7ede-b43c-37b63c8d5c1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_01a01620-5861-7c9f-8937-95a8c4aef522" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-7ede-b43c-37b63c8d5c1f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_01a01620-5861-7af9-9a13-6946a50e3089" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-7ede-b43c-37b63c8d5c1f" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_01a01620-5861-7af9-9a13-6946a50e3089" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a01620-5861-7af9-9a13-6946a50e3089_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a01620-5861-7af9-9a13-6946a50e3089" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a01620-5861-7af9-9a13-6946a50e3089_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a01620-5861-7215-90b3-5568601a36c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_01a01620-5861-7af9-9a13-6946a50e3089" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a01620-5861-7215-90b3-5568601a36c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NationalBankOfNewYorkCityMember_01a01620-5861-7a70-ba1c-d3d19cc54cf9" xlink:href="newt-20260930.xsd#newt_NationalBankOfNewYorkCityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_01a01620-5861-7215-90b3-5568601a36c6" xlink:to="loc_newt_NationalBankOfNewYorkCityMember_01a01620-5861-7a70-ba1c-d3d19cc54cf9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-7a10-abb4-8bd3fc245e12" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_01a01620-5861-7ede-b43c-37b63c8d5c1f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-7a10-abb4-8bd3fc245e12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-7a10-abb4-8bd3fc245e12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-7a10-abb4-8bd3fc245e12" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-7a10-abb4-8bd3fc245e12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-7c5b-890f-35d2ff00c49d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_01a01620-5861-7a10-abb4-8bd3fc245e12" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-7c5b-890f-35d2ff00c49d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CoreDepositsMember_01a01620-5861-7f78-9768-e864f63ae76c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CoreDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_01a01620-5861-7c5b-890f-35d2ff00c49d" xlink:to="loc_us-gaap_CoreDepositsMember_01a01620-5861-7f78-9768-e864f63ae76c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_01a01620-5861-72b0-a047-6b09de266ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_01a01620-5861-7c9f-8937-95a8c4aef522" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_01a01620-5861-72b0-a047-6b09de266ac2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSAmortizationDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#GOODWILLANDINTANGIBLEASSETSAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/GOODWILLANDINTANGIBLEASSETSAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7866-ab34-367303277d95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-71be-908b-cd5fe4f95d9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7866-ab34-367303277d95" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-71be-908b-cd5fe4f95d9e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_01a01620-5861-719c-a59c-3a2a4a3f110a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-71be-908b-cd5fe4f95d9e" xlink:to="loc_srt_ConsolidationItemsAxis_01a01620-5861-719c-a59c-3a2a4a3f110a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a01620-5861-719c-a59c-3a2a4a3f110a_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_01a01620-5861-719c-a59c-3a2a4a3f110a" xlink:to="loc_srt_ConsolidationItemsDomain_01a01620-5861-719c-a59c-3a2a4a3f110a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a01620-5861-783c-b533-57c301695845" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_01a01620-5861-719c-a59c-3a2a4a3f110a" xlink:to="loc_srt_ConsolidationItemsDomain_01a01620-5861-783c-b533-57c301695845" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_01a01620-5861-781a-861d-3964e71dd9a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_01a01620-5861-783c-b533-57c301695845" xlink:to="loc_us-gaap_OperatingSegmentsMember_01a01620-5861-781a-861d-3964e71dd9a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7d55-97f6-62df19c98166" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_01a01620-5861-71be-908b-cd5fe4f95d9e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7d55-97f6-62df19c98166" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5861-7d55-97f6-62df19c98166_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7d55-97f6-62df19c98166" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5861-7d55-97f6-62df19c98166_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5861-7e8b-a1a9-0f4ef20f4d36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5861-7d55-97f6-62df19c98166" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5861-7e8b-a1a9-0f4ef20f4d36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_BankingSegmentMember_01a01620-5861-736a-8e55-c930b4b95733" xlink:href="newt-20260930.xsd#newt_BankingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5861-7e8b-a1a9-0f4ef20f4d36" xlink:to="loc_newt_BankingSegmentMember_01a01620-5861-736a-8e55-c930b4b95733" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_01a01620-5861-7a24-a6ee-5a3736c43032" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_01a01620-5861-7866-ab34-367303277d95" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_01a01620-5861-7a24-a6ee-5a3736c43032" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSFairValueLevelsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#FAIRVALUEMEASUREMENTSFairValueLevelsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSFairValueLevelsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7f10-b787-2b08c7829dec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7f10-b787-2b08c7829dec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7f10-b787-2b08c7829dec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7f10-b787-2b08c7829dec" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7f10-b787-2b08c7829dec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7c19-a1cb-a63043c4b1a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7f10-b787-2b08c7829dec" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7c19-a1cb-a63043c4b1a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_01a01620-5861-71c6-bc17-404f09a10337" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7c19-a1cb-a63043c4b1a8" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_01a01620-5861-71c6-bc17-404f09a10337" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_01a01620-5861-794b-a3ac-bb3da8345f5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7c19-a1cb-a63043c4b1a8" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_01a01620-5861-794b-a3ac-bb3da8345f5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-7fd6-a276-bc75d57c9959" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7c19-a1cb-a63043c4b1a8" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-7fd6-a276-bc75d57c9959" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74c9-9ee6-c51bd55c5193" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74c9-9ee6-c51bd55c5193" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-74c9-9ee6-c51bd55c5193_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74c9-9ee6-c51bd55c5193" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-74c9-9ee6-c51bd55c5193_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-72ea-8f21-7b2a3c282db8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74c9-9ee6-c51bd55c5193" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-72ea-8f21-7b2a3c282db8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-7a9d-86ff-f51b94a11443" xlink:href="newt-20260930.xsd#newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-72ea-8f21-7b2a3c282db8" xlink:to="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-7a9d-86ff-f51b94a11443" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-708e-b506-dc701223afca" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-708e-b506-dc701223afca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-708e-b506-dc701223afca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-708e-b506-dc701223afca" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-708e-b506-dc701223afca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7955-ab34-1107d8ee2f6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-708e-b506-dc701223afca" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7955-ab34-1107d8ee2f6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasurySecuritiesMember_01a01620-5861-72aa-9767-ee74d5739ff3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasurySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7955-ab34-1107d8ee2f6a" xlink:to="loc_us-gaap_USTreasurySecuritiesMember_01a01620-5861-72aa-9767-ee74d5739ff3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-5861-7d64-a745-f0198301bfbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-5861-7d64-a745-f0198301bfbf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-5861-7d64-a745-f0198301bfbf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-5861-7d64-a745-f0198301bfbf" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-5861-7d64-a745-f0198301bfbf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-5861-7b9b-88a4-36022f2cd728" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupClassificationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_01a01620-5861-7d64-a745-f0198301bfbf" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-5861-7b9b-88a4-36022f2cd728" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-5861-7f63-82f8-c1bbea4ab600" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_01a01620-5861-7b9b-88a4-36022f2cd728" xlink:to="loc_us-gaap_DisposalGroupDisposedOfBySaleNotDiscontinuedOperationsMember_01a01620-5861-7f63-82f8-c1bbea4ab600" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-5861-7506-b03e-ff052789df51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-7a2f-9559-20fa07472747" xlink:to="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-5861-7506-b03e-ff052789df51" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-5861-7506-b03e-ff052789df51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-5861-7506-b03e-ff052789df51" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-5861-7506-b03e-ff052789df51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-5861-7d6f-a657-0d772d32b637" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_01a01620-5861-7506-b03e-ff052789df51" xlink:to="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-5861-7d6f-a657-0d772d32b637" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-5861-7305-afdc-f3055a32f019" xlink:href="newt-20260930.xsd#newt_NewtekTechnologySolutionsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_01a01620-5861-7d6f-a657-0d772d32b637" xlink:to="loc_newt_NewtekTechnologySolutionsIncMember_01a01620-5861-7305-afdc-f3055a32f019" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:to="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_01a01620-5861-7b1c-a6c2-49cd458cedfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_01a01620-5861-7b1c-a6c2-49cd458cedfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-5861-7822-817a-d32569de627d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansReceivableHeldForSaleAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_LoansReceivableHeldForSaleAmount_01a01620-5861-7822-817a-d32569de627d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-5861-7725-b68a-e8bb5c0dbd90" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-5861-7725-b68a-e8bb5c0dbd90" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualsInSecuritizationFairValue_01a01620-5861-707e-9123-c320ad54e5bc" xlink:href="newt-20260930.xsd#newt_ResidualsInSecuritizationFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_newt_ResidualsInSecuritizationFairValue_01a01620-5861-707e-9123-c320ad54e5bc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-5861-75a0-bb57-10b55b65a0e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-5861-75a0-bb57-10b55b65a0e3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-5861-7396-8452-9fc43f5d7eac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-5861-7396-8452-9fc43f5d7eac" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_01a01620-5861-7581-851e-ff05954afa70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_DerivativeAssets_01a01620-5861-7581-851e-ff05954afa70" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_01a01620-5861-75af-b884-dfd1de2499a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeAssets_01a01620-5861-7581-851e-ff05954afa70" xlink:to="loc_us-gaap_DerivativeAssetStatementOfFinancialPositionExtensibleEnumeration_01a01620-5861-75af-b884-dfd1de2499a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_01a01620-5861-778d-8871-a4e82de8cb53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsFairValueDisclosureAbstract_01a01620-5861-7a87-a8c0-27f74b565525" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_01a01620-5861-778d-8871-a4e82de8cb53" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_01a01620-5861-7dee-b13c-88a64aaa9f73" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_01a01620-5861-7dee-b13c-88a64aaa9f73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_01a01620-5861-728d-80fe-c26ef4dccd89" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_01a01620-5861-7dee-b13c-88a64aaa9f73" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_01a01620-5861-728d-80fe-c26ef4dccd89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_01a01620-5861-7a52-9bb4-8b307faab025" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosureAbstract_01a01620-5861-7dee-b13c-88a64aaa9f73" xlink:to="loc_us-gaap_LiabilitiesFairValueDisclosure_01a01620-5861-7a52-9bb4-8b307faab025" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-5861-70bc-91af-b7f90afd7493" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssued_01a01620-5861-70bc-91af-b7f90afd7493" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-5861-7325-a910-31bce2132b6f" xlink:href="newt-20260930.xsd#newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-70fd-961e-89ec32ca330e" xlink:to="loc_newt_DisposalGroupIncludingDiscontinuedOperationConsiderationSharesIssuedValuePerShare_01a01620-5861-7325-a910-31bce2132b6f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSLevelIIIRollforwardDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#FAIRVALUEMEASUREMENTSLevelIIIRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSLevelIIIRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7944-bf02-a8fd8a1c9933" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7944-bf02-a8fd8a1c9933" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_01a01620-5861-78d7-8f90-c0b1b5e316b1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_01a01620-5861-78d7-8f90-c0b1b5e316b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-78d7-8f90-c0b1b5e316b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_01a01620-5861-78d7-8f90-c0b1b5e316b1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-78d7-8f90-c0b1b5e316b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_01a01620-5861-78d7-8f90-c0b1b5e316b1" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LoansHeldForInvestmentMember_01a01620-5861-7cac-8bf5-cd742b720fff" xlink:href="newt-20260930.xsd#newt_LoansHeldForInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_newt_LoansHeldForInvestmentMember_01a01620-5861-7cac-8bf5-cd742b720fff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LoansHeldForSaleMember_01a01620-5861-7be0-84dc-1bb6772566ee" xlink:href="newt-20260930.xsd#newt_LoansHeldForSaleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_newt_LoansHeldForSaleMember_01a01620-5861-7be0-84dc-1bb6772566ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsMember_01a01620-5861-7341-8ced-e7e873936352" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_us-gaap_InvestmentsMember_01a01620-5861-7341-8ced-e7e873936352" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualsInSecuritizationMember_01a01620-5861-7f5d-a33c-5f57a451c55c" xlink:href="newt-20260930.xsd#newt_ResidualsInSecuritizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_newt_ResidualsInSecuritizationMember_01a01620-5861-7f5d-a33c-5f57a451c55c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ServicingAssetsMember_01a01620-5861-7290-9e0f-b7c25755cd4d" xlink:href="newt-20260930.xsd#newt_ServicingAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_newt_ServicingAssetsMember_01a01620-5861-7290-9e0f-b7c25755cd4d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_01a01620-5861-7d45-adcf-c68ba12a689a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_01a01620-5861-7fb8-b54f-b831b77c0278" xlink:to="loc_us-gaap_WarrantMember_01a01620-5861-7d45-adcf-c68ba12a689a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74a3-b059-7cd6d7591439" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74a3-b059-7cd6d7591439" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-74a3-b059-7cd6d7591439_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74a3-b059-7cd6d7591439" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-74a3-b059-7cd6d7591439_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7695-b830-a1de77c50ed1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-74a3-b059-7cd6d7591439" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7695-b830-a1de77c50ed1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-7ed4-8711-2e250954d300" xlink:href="newt-20260930.xsd#newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7695-b830-a1de77c50ed1" xlink:to="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-7ed4-8711-2e250954d300" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NatureOfGainLossAxis_01a01620-5861-7170-806b-11ffa8f6b4e0" xlink:href="newt-20260930.xsd#newt_NatureOfGainLossAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:to="loc_newt_NatureOfGainLossAxis_01a01620-5861-7170-806b-11ffa8f6b4e0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7170-806b-11ffa8f6b4e0_default" xlink:href="newt-20260930.xsd#newt_NatureOfGainLossAxisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_newt_NatureOfGainLossAxis_01a01620-5861-7170-806b-11ffa8f6b4e0" xlink:to="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7170-806b-11ffa8f6b4e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7260-bd68-21c460fa780e" xlink:href="newt-20260930.xsd#newt_NatureOfGainLossAxisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_newt_NatureOfGainLossAxis_01a01620-5861-7170-806b-11ffa8f6b4e0" xlink:to="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7260-bd68-21c460fa780e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ChangesInValuationInputsOrAdjustmentsMember_01a01620-5861-740b-b5cf-0b255d543138" xlink:href="newt-20260930.xsd#newt_ChangesInValuationInputsOrAdjustmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7260-bd68-21c460fa780e" xlink:to="loc_newt_ChangesInValuationInputsOrAdjustmentsMember_01a01620-5861-740b-b5cf-0b255d543138" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FactorsOtherThanChangesInValuationInputsOrAdjustmentsMember_01a01620-5861-7217-9e60-0467868843b2" xlink:href="newt-20260930.xsd#newt_FactorsOtherThanChangesInValuationInputsOrAdjustmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_NatureOfGainLossAxisDomain_01a01620-5861-7260-bd68-21c460fa780e" xlink:to="loc_newt_FactorsOtherThanChangesInValuationInputsOrAdjustmentsMember_01a01620-5861-7217-9e60-0467868843b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7882-aef8-dda97e293e05" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-785d-9111-1f0f2b47b23a" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7882-aef8-dda97e293e05" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7882-aef8-dda97e293e05_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7882-aef8-dda97e293e05" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7882-aef8-dda97e293e05_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-735b-9323-c2e7acbce2c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7882-aef8-dda97e293e05" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-735b-9323-c2e7acbce2c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-5861-7eee-bdcd-593260be69c2" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-735b-9323-c2e7acbce2c1" xlink:to="loc_newt_SBA7aLoanMember_01a01620-5861-7eee-bdcd-593260be69c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ConventionalLoansMember_01a01620-5861-7cc7-8909-46b76a1db019" xlink:href="newt-20260930.xsd#newt_ConventionalLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-735b-9323-c2e7acbce2c1" xlink:to="loc_newt_ConventionalLoansMember_01a01620-5861-7cc7-8909-46b76a1db019" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7944-bf02-a8fd8a1c9933" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_01a01620-5861-73ff-a276-bcb1f22d6212" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_01a01620-5861-73ff-a276-bcb1f22d6212" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansHeldForSaleAndHeldForInvestment_01a01620-5861-732d-b6ff-25849e662de0" xlink:href="newt-20260930.xsd#newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansHeldForSaleAndHeldForInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansHeldForSaleAndHeldForInvestment_01a01620-5861-732d-b6ff-25849e662de0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansFairValueAndLowerOfCostOrMarket_01a01620-5861-769b-82f5-6053d27e3dc5" xlink:href="newt-20260930.xsd#newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansFairValueAndLowerOfCostOrMarket"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReclassificationOfLoansFairValueAndLowerOfCostOrMarket_01a01620-5861-769b-82f5-6053d27e3dc5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_01a01620-5861-7dca-ab91-37b90c5b62d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_01a01620-5861-7dca-ab91-37b90c5b62d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_01a01620-5861-7797-9b9f-4b23ff20d613" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_01a01620-5861-7797-9b9f-4b23ff20d613" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_01a01620-5861-761f-94e3-87e2bb686c14" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_01a01620-5861-761f-94e3-87e2bb686c14" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues_01a01620-5861-7054-8115-82929f5160c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetIssues_01a01620-5861-7054-8115-82929f5160c1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesFromOtherAssetClass_01a01620-5861-79be-ab6b-3695dc8b7443" xlink:href="newt-20260930.xsd#newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesFromOtherAssetClass"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchasesFromOtherAssetClass_01a01620-5861-79be-ab6b-3695dc8b7443" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOfCapital_01a0cef8-3344-7e46-8b3f-591c3bf299a2" xlink:href="newt-20260930.xsd#newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_newt_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetReturnOfCapital_01a0cef8-3344-7e46-8b3f-591c3bf299a2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_01a01620-5861-7e24-a765-d385d7fdabd0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_01a01620-5861-7e24-a765-d385d7fdabd0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_01a01620-5861-7805-b9e8-afd3bb1a0296" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_01a01620-5861-7805-b9e8-afd3bb1a0296" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_01a01620-5861-7cd0-b8d7-1891e0431576" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_01a01620-5861-7af5-a160-4d480b66c376" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_01a01620-5861-7cd0-b8d7-1891e0431576" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_01a01620-5861-7327-8554-a7c4af294c93" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-5861-7cd1-a60a-ca26bf665ba2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7944-bf02-a8fd8a1c9933" xlink:to="loc_us-gaap_TransferOfLoansHeldForSaleToPortfolioLoans1_01a01620-5861-7cd1-a60a-ca26bf665ba2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture_01a0cef9-0575-749f-a456-32e5df024002" xlink:href="newt-20260930.xsd#newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7944-bf02-a8fd8a1c9933" xlink:to="loc_newt_NoncashOrPartNoncashTransactionAcquisitionOfJointVenture_01a0cef9-0575-749f-a456-32e5df024002" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSUnobservableUnitsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#FAIRVALUEMEASUREMENTSUnobservableUnitsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSUnobservableUnitsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a01620-5861-73a5-8a6b-e14a25f46f35" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:to="loc_srt_RangeAxis_01a01620-5861-73a5-8a6b-e14a25f46f35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5861-73a5-8a6b-e14a25f46f35_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_01a01620-5861-73a5-8a6b-e14a25f46f35" xlink:to="loc_srt_RangeMember_01a01620-5861-73a5-8a6b-e14a25f46f35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5861-71dc-a8a0-81b05ee797f5" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_01a01620-5861-73a5-8a6b-e14a25f46f35" xlink:to="loc_srt_RangeMember_01a01620-5861-71dc-a8a0-81b05ee797f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_01a01620-5861-7877-bab9-7ce10d267447" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-71dc-a8a0-81b05ee797f5" xlink:to="loc_srt_WeightedAverageMember_01a01620-5861-7877-bab9-7ce10d267447" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a01620-5861-77af-8619-e00f155b8abc" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-71dc-a8a0-81b05ee797f5" xlink:to="loc_srt_MinimumMember_01a01620-5861-77af-8619-e00f155b8abc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a01620-5861-7bec-9647-acabf874ae04" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5861-71dc-a8a0-81b05ee797f5" xlink:to="loc_srt_MaximumMember_01a01620-5861-7bec-9647-acabf874ae04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-770a-a666-7f0be532eddc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-770a-a666-7f0be532eddc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-770a-a666-7f0be532eddc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-770a-a666-7f0be532eddc" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-770a-a666-7f0be532eddc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-770a-a666-7f0be532eddc" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_MeasurementInputMarketYieldsMember_01a01620-5861-7ff6-9380-347a12670bf1" xlink:href="newt-20260930.xsd#newt_MeasurementInputMarketYieldsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_newt_MeasurementInputMarketYieldsMember_01a01620-5861-7ff6-9380-347a12670bf1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPrepaymentRateMember_01a01620-5861-7096-90fe-1717c7194713" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputPrepaymentRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_us-gaap_MeasurementInputPrepaymentRateMember_01a01620-5861-7096-90fe-1717c7194713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDefaultRateMember_01a01620-5861-7936-9e34-80bb103fa14c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputDefaultRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_us-gaap_MeasurementInputDefaultRateMember_01a01620-5861-7936-9e34-80bb103fa14c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_MeasurementInputCostMember_01a01620-5861-78a1-8d1b-f85d7634efa8" xlink:href="newt-20260930.xsd#newt_MeasurementInputCostMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_newt_MeasurementInputCostMember_01a01620-5861-78a1-8d1b-f85d7634efa8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_MeasurementInputWeightedAverageCostOfCapitalMember_01a01620-5861-7e32-b075-be34bb14e64a" xlink:href="newt-20260930.xsd#newt_MeasurementInputWeightedAverageCostOfCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_newt_MeasurementInputWeightedAverageCostOfCapitalMember_01a01620-5861-7e32-b075-be34bb14e64a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputPriceVolatilityMember_01a01620-5861-737e-a3b8-0d5bb2ebe8f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputPriceVolatilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_us-gaap_MeasurementInputPriceVolatilityMember_01a01620-5861-737e-a3b8-0d5bb2ebe8f3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_MeasurementInputDividendYieldMember_01a01620-5861-7ad3-9758-cba6cfac0964" xlink:href="newt-20260930.xsd#newt_MeasurementInputDividendYieldMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_newt_MeasurementInputDividendYieldMember_01a01620-5861-7ad3-9758-cba6cfac0964" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_01a01620-5861-7cc5-a885-48bf9d03ccd7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputRiskFreeInterestRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7f03-8e84-5bcbfbc9c54e" xlink:to="loc_us-gaap_MeasurementInputRiskFreeInterestRateMember_01a01620-5861-7cc5-a885-48bf9d03ccd7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7439-a656-37c1bebe3081" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7439-a656-37c1bebe3081" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7439-a656-37c1bebe3081_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7439-a656-37c1bebe3081" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-7439-a656-37c1bebe3081_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-729f-97e1-5568213c1385" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5861-7439-a656-37c1bebe3081" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-729f-97e1-5568213c1385" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnguaranteedAccrualInvestmentsMember_01a01620-5861-721f-abb3-5e2ef53ede4f" xlink:href="newt-20260930.xsd#newt_UnguaranteedAccrualInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-729f-97e1-5568213c1385" xlink:to="loc_newt_UnguaranteedAccrualInvestmentsMember_01a01620-5861-721f-abb3-5e2ef53ede4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnguaranteedNonAccrualInvestmentsMember_01a01620-5861-75aa-83e5-d436cead70ee" xlink:href="newt-20260930.xsd#newt_UnguaranteedNonAccrualInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5861-729f-97e1-5568213c1385" xlink:to="loc_newt_UnguaranteedNonAccrualInvestmentsMember_01a01620-5861-75aa-83e5-d436cead70ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-777f-a533-f0979b812887" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-777f-a533-f0979b812887" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-777f-a533-f0979b812887_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-777f-a533-f0979b812887" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-777f-a533-f0979b812887_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7178-8db6-64fa62dad59b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_01a01620-5861-777f-a533-f0979b812887" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7178-8db6-64fa62dad59b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-76ae-8afe-be9f784a2c02" xlink:href="newt-20260930.xsd#newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_01a01620-5861-7178-8db6-64fa62dad59b" xlink:to="loc_newt_InvestmentAffiliatedIssuerControlledNotMajorityOwnedAndNoncontrolledMember_01a01620-5861-76ae-8afe-be9f784a2c02" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7ad5-b51d-0d8f7357a5d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a01620-5861-763e-ae92-28f0255a7b59" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7ad5-b51d-0d8f7357a5d2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7ad5-b51d-0d8f7357a5d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7ad5-b51d-0d8f7357a5d2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7ad5-b51d-0d8f7357a5d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-71ee-aeab-8506de2b7df4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-7ad5-b51d-0d8f7357a5d2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-71ee-aeab-8506de2b7df4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-75a8-aec2-e4849c05b90e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-71ee-aeab-8506de2b7df4" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-75a8-aec2-e4849c05b90e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-5861-7118-83c0-78b3ce96cdf0" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossFairValueDisclosure_01a01620-5861-7118-83c0-78b3ce96cdf0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossMeasurementInput_01a01620-5861-72a5-9345-bb6b93019866" xlink:href="newt-20260930.xsd#newt_FinancingReceivableBeforeAllowanceForCreditLossMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_newt_FinancingReceivableBeforeAllowanceForCreditLossMeasurementInput_01a01620-5861-72a5-9345-bb6b93019866" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_01a01620-5861-7e4d-b8a5-5691935f4b5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansHeldForSaleFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_LoansHeldForSaleFairValueDisclosure_01a01620-5861-7e4d-b8a5-5691935f4b5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansHeldForSaleMeasurementInput_01a01620-5861-7459-b8fd-870ffd98be76" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LoansHeldForSaleMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_LoansHeldForSaleMeasurementInput_01a01620-5861-7459-b8fd-870ffd98be76" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-5861-7c95-add1-6429403842e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_01a01620-5861-7c95-add1-6429403842e1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_InvestmentOwnedFairValueMeasurementInput_01a01620-5861-735c-b701-28a5b377f990" xlink:href="newt-20260930.xsd#newt_InvestmentOwnedFairValueMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_newt_InvestmentOwnedFairValueMeasurementInput_01a01620-5861-735c-b701-28a5b377f990" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualsInSecuritizationFairValue_01a01620-5861-7ea1-b993-de5c699318fa" xlink:href="newt-20260930.xsd#newt_ResidualsInSecuritizationFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_newt_ResidualsInSecuritizationFairValue_01a01620-5861-7ea1-b993-de5c699318fa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ResidualsInSecuritizationFairValueMeasurementInput_01a01620-5861-7e52-9a7d-741d52a2151d" xlink:href="newt-20260930.xsd#newt_ResidualsInSecuritizationFairValueMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_newt_ResidualsInSecuritizationFairValueMeasurementInput_01a01620-5861-7e52-9a7d-741d52a2151d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-5861-7eac-861f-61637b5998e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtFairValueAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_ServicingAssetAtFairValueAmount_01a01620-5861-7eac-861f-61637b5998e2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetMeasurementInput_01a01620-5861-7431-901b-8590988586fa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_ServicingAssetMeasurementInput_01a01620-5861-7431-901b-8590988586fa" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstanding_01a01620-5861-7128-aeae-378856238e1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantsAndRightsOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_WarrantsAndRightsOutstanding_01a01620-5861-7128-aeae-378856238e1c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_01a01620-5861-74c9-a3c8-7ed0a11b441a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantsAndRightsOutstandingMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a01620-5861-7c13-8199-e1170f166f63" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingMeasurementInput_01a01620-5861-74c9-a3c8-7ed0a11b441a" xlink:type="arc" order="11"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSEstimatedFairValueofOtherFinancialInstrumentsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#FAIRVALUEMEASUREMENTSEstimatedFairValueofOtherFinancialInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSEstimatedFairValueofOtherFinancialInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a19e08-8d88-7d31-b285-bdf9cd5efba4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a19e08-8d88-798a-9b45-a1fcd09b6fcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a19e08-8d88-7d31-b285-bdf9cd5efba4" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a19e08-8d88-798a-9b45-a1fcd09b6fcc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a19e08-8d88-7daf-9e7d-93c5221df4e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a19e08-8d88-798a-9b45-a1fcd09b6fcc" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a19e08-8d88-7daf-9e7d-93c5221df4e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7daf-9e7d-93c5221df4e3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a19e08-8d88-7daf-9e7d-93c5221df4e3" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7daf-9e7d-93c5221df4e3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7b76-b3b4-4b286ad6c1da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a19e08-8d88-7daf-9e7d-93c5221df4e3" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7b76-b3b4-4b286ad6c1da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_01a19e08-8d88-70f8-8a3e-1af6e8251b88" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7b76-b3b4-4b286ad6c1da" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_01a19e08-8d88-70f8-8a3e-1af6e8251b88" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_01a19e08-8d88-7061-90a9-4c3ddfe13e1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7b76-b3b4-4b286ad6c1da" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_01a19e08-8d88-7061-90a9-4c3ddfe13e1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01a19e08-8d88-7415-8aee-f9c502e66851" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a19e08-8d88-7b76-b3b4-4b286ad6c1da" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01a19e08-8d88-7415-8aee-f9c502e66851" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a19e08-8d88-7d07-a797-0601a072a548" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a19e08-8d88-798a-9b45-a1fcd09b6fcc" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a19e08-8d88-7d07-a797-0601a072a548" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7d07-a797-0601a072a548_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a19e08-8d88-7d07-a797-0601a072a548" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7d07-a797-0601a072a548_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7bc0-8a87-1d869f768421" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a19e08-8d88-7d07-a797-0601a072a548" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7bc0-8a87-1d869f768421" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CashAndDueFromBanksMember_01a19e08-8d88-770e-96f5-6448177875ee" xlink:href="newt-20260930.xsd#newt_CashAndDueFromBanksMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7bc0-8a87-1d869f768421" xlink:to="loc_newt_CashAndDueFromBanksMember_01a19e08-8d88-770e-96f5-6448177875ee" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_RestrictedCashMember_01a19e08-8d88-7a1c-8e50-5fb6081d0218" xlink:href="newt-20260930.xsd#newt_RestrictedCashMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7bc0-8a87-1d869f768421" xlink:to="loc_newt_RestrictedCashMember_01a19e08-8d88-7a1c-8e50-5fb6081d0218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositsMember_01a19e08-8d88-7f3c-937a-cd9cc303dd59" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a19e08-8d88-7bc0-8a87-1d869f768421" xlink:to="loc_us-gaap_InterestBearingDepositsMember_01a19e08-8d88-7f3c-937a-cd9cc303dd59" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a19e08-8d88-7cd9-8bff-572024bee232" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_01a19e08-8d88-798a-9b45-a1fcd09b6fcc" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a19e08-8d88-7cd9-8bff-572024bee232" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a19e08-8d88-7cd9-8bff-572024bee232_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a19e08-8d88-7cd9-8bff-572024bee232" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a19e08-8d88-7cd9-8bff-572024bee232_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a19e08-8d88-7de6-8159-9d01df9ac475" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_01a19e08-8d88-7cd9-8bff-572024bee232" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_01a19e08-8d88-7de6-8159-9d01df9ac475" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:href="newt-20260930.xsd#newt_CarryingAmountAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a19e08-8d88-7d31-b285-bdf9cd5efba4" xlink:to="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Cash_01a01620-5861-7f7a-9008-5b61ca94d6b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Cash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_Cash_01a01620-5861-7f7a-9008-5b61ca94d6b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_01a01620-5861-7a07-be2a-5a59b59ebfa4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_RestrictedCash_01a01620-5861-7a07-be2a-5a59b59ebfa4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueFromBanks_01a01620-5861-701a-8c3c-4da28ca45c5c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DueFromBanks"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_DueFromBanks_01a01620-5861-701a-8c3c-4da28ca45c5c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-5861-70c5-acf7-94d265523458" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarket_01a01620-5861-70c5-acf7-94d265523458" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-5861-7206-afa5-3428485cf8d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss_01a01620-5861-7206-afa5-3428485cf8d8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRealEstate_01a01620-5861-797d-8b61-e050ce7de7d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherRealEstate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_OtherRealEstate_01a01620-5861-797d-8b61-e050ce7de7d0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServicingAssetAtAmortizedValue_01a01620-5861-72ff-a712-3634714f3223" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ServicingAssetAtAmortizedValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_ServicingAssetAtAmortizedValue_01a01620-5861-72ff-a712-3634714f3223" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_01a01620-5861-7b6d-a127-80867369766f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_FederalHomeLoanBankStockAndFederalReserveBankStock_01a01620-5861-7b6d-a127-80867369766f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositTimeDeposits_01a01620-5861-747f-a34a-43e9581897b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositTimeDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_InterestBearingDomesticDepositTimeDeposits_01a01620-5861-747f-a34a-43e9581897b2" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a01620-5861-79a2-8592-ae233096386d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_CarryingAmountAbstract_01a01620-5861-73dd-b1d5-1fb8dbe089d3" xlink:to="loc_us-gaap_LongTermDebt_01a01620-5861-79a2-8592-ae233096386d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueNetAssetLiabilityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_01a19e08-8d88-7d31-b285-bdf9cd5efba4" xlink:to="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_01a01620-5861-7893-b73f-4091c25d3b8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_01a01620-5861-7893-b73f-4091c25d3b8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketFairValueDisclosure_01a01620-5861-7d15-ba71-1d344955a012" xlink:href="newt-20260930.xsd#newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_newt_FinancingReceivableHeldForSaleLowerOfCostOrMarketFairValueDisclosure_01a01620-5861-7d15-ba71-1d344955a012" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FinancingReceivableFairValueDisclosure_01a01620-5861-7f39-8fbe-bb3a2c1d7dfc" xlink:href="newt-20260930.xsd#newt_FinancingReceivableFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_newt_FinancingReceivableFairValueDisclosure_01a01620-5861-7f39-8fbe-bb3a2c1d7dfc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_OtherRealEstateFairValueDisclosure_01a01620-5861-758c-a77a-f1dab23a4c6b" xlink:href="newt-20260930.xsd#newt_OtherRealEstateFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_newt_OtherRealEstateFairValueDisclosure_01a01620-5861-758c-a77a-f1dab23a4c6b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ServicingAssetLowerOfCostOrMarketFairValueDisclosure_01a01620-5861-7aed-a9f4-09fb8b0abd10" xlink:href="newt-20260930.xsd#newt_ServicingAssetLowerOfCostOrMarketFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_newt_ServicingAssetLowerOfCostOrMarketFairValueDisclosure_01a01620-5861-7aed-a9f4-09fb8b0abd10" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure_01a01620-5861-75a6-8c22-24a48f68d184" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_us-gaap_InvestmentInFederalHomeLoanBankStockFairValueDisclosure_01a01620-5861-75a6-8c22-24a48f68d184" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositsFairValueDisclosure_01a01620-5861-7b1a-ab30-d33c1a0d3aec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_us-gaap_DepositsFairValueDisclosure_01a01620-5861-7b1a-ab30-d33c1a0d3aec" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_01a01620-5861-7ec7-bfac-a7f19a18a568" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueNetAssetLiabilityAbstract_01a01620-5861-7ab9-bf42-8affae0637a0" xlink:to="loc_us-gaap_LongTermDebtFairValue_01a01620-5861-7ec7-bfac-a7f19a18a568" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSFairValueofDebtDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#FAIRVALUEMEASUREMENTSFairValueofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/FAIRVALUEMEASUREMENTSFairValueofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-735f-bb33-d5ca406c18d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-735f-bb33-d5ca406c18d5" xlink:to="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7e1b-be64-0b21b1abeaf7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7e1b-be64-0b21b1abeaf7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7e1b-be64-0b21b1abeaf7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7e1b-be64-0b21b1abeaf7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7e1b-be64-0b21b1abeaf7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7e1b-be64-0b21b1abeaf7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-5861-748e-8b23-584ea8bfa8e9" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_A2026NotesMember_01a01620-5861-748e-8b23-584ea8bfa8e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2028NotesMember_01a01620-5861-7e19-83d7-8ad4d5417911" xlink:href="newt-20260930.xsd#newt_A2028NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_A2028NotesMember_01a01620-5861-7e19-83d7-8ad4d5417911" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a01620-5861-77ad-9351-85068c90b42c" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_A20298.50NotesMember_01a01620-5861-77ad-9351-85068c90b42c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.625NotesMember_01a01620-5861-700e-a690-a52557b20ffa" xlink:href="newt-20260930.xsd#newt_A20298.625NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_A20298.625NotesMember_01a01620-5861-700e-a690-a52557b20ffa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-5861-76d8-b1c7-9bc3f4d1358b" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_A20318.50NotesMember_01a01620-5861-76d8-b1c7-9bc3f4d1358b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PrivateParentCompanyNotesMember_01a01620-5861-7658-9e79-979e417231d0" xlink:href="newt-20260930.xsd#newt_PrivateParentCompanyNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_PrivateParentCompanyNotesMember_01a01620-5861-7658-9e79-979e417231d0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsMember_01a01620-5861-7aee-83c7-443e20e9e726" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_SecuritizationTrustsMember_01a01620-5861-7aee-83c7-443e20e9e726" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_FHLBBorrowingsMember_01a01620-5861-71d7-b69b-0b0c67d30ae0" xlink:href="newt-20260930.xsd#newt_FHLBBorrowingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_FHLBBorrowingsMember_01a01620-5861-71d7-b69b-0b0c67d30ae0" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_BankBorrowingsMember_01a01620-5861-762b-985a-d653b0f4501f" xlink:href="newt-20260930.xsd#newt_BankBorrowingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7c4b-b083-c3451298d8b8" xlink:to="loc_newt_BankBorrowingsMember_01a01620-5861-762b-985a-d653b0f4501f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-765e-88bd-28a2618d1bea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-765e-88bd-28a2618d1bea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-765e-88bd-28a2618d1bea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-765e-88bd-28a2618d1bea" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-765e-88bd-28a2618d1bea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7245-a44f-8776cbced2d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-765e-88bd-28a2618d1bea" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7245-a44f-8776cbced2d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7871-ad2b-eb754b8086c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7245-a44f-8776cbced2d6" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7871-ad2b-eb754b8086c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-71ac-a42b-6bf48d1b0920" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-71ac-a42b-6bf48d1b0920" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-71ac-a42b-6bf48d1b0920_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-71ac-a42b-6bf48d1b0920" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-71ac-a42b-6bf48d1b0920_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7742-9c6e-61beb456095b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_01a01620-5861-71ac-a42b-6bf48d1b0920" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7742-9c6e-61beb456095b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_01a01620-5861-7752-adac-2d258d04e77b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7742-9c6e-61beb456095b" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_01a01620-5861-7752-adac-2d258d04e77b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-7126-a9fc-5d92de91ff60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_01a01620-5861-7742-9c6e-61beb456095b" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01a01620-5861-7126-a9fc-5d92de91ff60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7002-899a-08b6d05c575d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7fce-a08b-8275a1245f07" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7002-899a-08b6d05c575d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7002-899a-08b6d05c575d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7002-899a-08b6d05c575d" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-7002-899a-08b6d05c575d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-790d-a674-69dd09c137e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_01a01620-5861-7002-899a-08b6d05c575d" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-790d-a674-69dd09c137e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputSharePriceMember_01a01620-5861-7b5a-a850-a57c33de0ff4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MeasurementInputSharePriceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_01a01620-5861-790d-a674-69dd09c137e9" xlink:to="loc_us-gaap_MeasurementInputSharePriceMember_01a01620-5861-7b5a-a850-a57c33de0ff4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a01620-5861-71ff-ae88-625254769c04" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-735f-bb33-d5ca406c18d5" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a01620-5861-71ff-ae88-625254769c04" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMeasurementInput_01a01620-5861-7d3c-bcfd-3ea6ad5c54ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-735f-bb33-d5ca406c18d5" xlink:to="loc_us-gaap_LongTermDebtMeasurementInput_01a01620-5861-7d3c-bcfd-3ea6ad5c54ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_01a01620-5861-7aea-a1cd-8da4eb178e66" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-735f-bb33-d5ca406c18d5" xlink:to="loc_us-gaap_LongTermDebtFairValue_01a01620-5861-7aea-a1cd-8da4eb178e66" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/DEPOSITSDepositsbyTypeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#DEPOSITSDepositsbyTypeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/DEPOSITSDepositsbyTypeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositLiabilityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositsTable_01a01620-5861-7406-b500-a820e14108d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDepositsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_TimeDepositsTable_01a01620-5861-7406-b500-a820e14108d7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_01a01620-5861-77cd-8979-c7905c077dfa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_TimeDepositsTable_01a01620-5861-7406-b500-a820e14108d7" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_01a01620-5861-77cd-8979-c7905c077dfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_01a01620-5861-77cd-8979-c7905c077dfa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_01a01620-5861-77cd-8979-c7905c077dfa" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_01a01620-5861-77cd-8979-c7905c077dfa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_01a01620-5861-75e7-a0af-c6b415ab44c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_01a01620-5861-77cd-8979-c7905c077dfa" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_01a01620-5861-75e7-a0af-c6b415ab44c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CertificatesOfDepositMember_01a01620-5861-71db-9bf1-b452ab96b9ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CertificatesOfDepositMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_01a01620-5861-75e7-a0af-c6b415ab44c8" xlink:to="loc_us-gaap_CertificatesOfDepositMember_01a01620-5861-71db-9bf1-b452ab96b9ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestBearingDepositLiabilities_01a01620-5861-78c3-8af4-3be381bda3d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestBearingDepositLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_NoninterestBearingDepositLiabilities_01a01620-5861-78c3-8af4-3be381bda3d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositChecking_01a01620-5861-735f-9df9-b9c25eeb3e43" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositChecking"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:to="loc_us-gaap_InterestBearingDomesticDepositChecking_01a01620-5861-735f-9df9-b9c25eeb3e43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositMoneyMarket_01a01620-5861-7ce6-aa76-dcdac8cb6f17" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositMoneyMarket"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:to="loc_us-gaap_InterestBearingDomesticDepositMoneyMarket_01a01620-5861-7ce6-aa76-dcdac8cb6f17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositSavings_01a01620-5861-7ed4-93aa-40ea89724f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositSavings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:to="loc_us-gaap_InterestBearingDomesticDepositSavings_01a01620-5861-7ed4-93aa-40ea89724f2a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositTimeDeposits_01a01620-5861-7e59-8585-91fe1dda3b4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositTimeDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:to="loc_us-gaap_InterestBearingDomesticDepositTimeDeposits_01a01620-5861-7e59-8585-91fe1dda3b4d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDepositLiabilities_01a01620-5861-7422-a6d9-2d30436a77f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDepositLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InterestBearingDepositLiabilitiesByComponentAbstract_01a01620-5861-7a12-8126-d16522c9026c" xlink:to="loc_us-gaap_InterestBearingDepositLiabilities_01a01620-5861-7422-a6d9-2d30436a77f2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Deposits_01a01620-5861-7117-8447-fe965635c219" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Deposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_Deposits_01a01620-5861-7117-8447-fe965635c219" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestBearingDomesticDepositBrokered_01a01620-5861-7341-8bb4-3ab35d46f9f6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestBearingDomesticDepositBrokered"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_InterestBearingDomesticDepositBrokered_01a01620-5861-7341-8bb4-3ab35d46f9f6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit_01a01620-5861-7cd5-9673-373bb1058087" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_TimeDepositsAtOrAboveFDICInsuranceLimit_01a01620-5861-7cd5-9673-373bb1058087" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1_01a01620-5861-7d6a-ab5f-afbbeec9e017" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DepositLiabilityLineItems_01a01620-5861-7ebb-bc15-02c8e5304d50" xlink:to="loc_us-gaap_DepositLiabilitiesReclassifiedAsLoansReceivable1_01a01620-5861-7d6a-ab5f-afbbeec9e017" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BORROWINGSLongtermDebtDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BORROWINGSLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BORROWINGSLongtermDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7d57-bdbd-5018af45b022" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7d57-bdbd-5018af45b022" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-72af-aa2d-1967e7ff3d53" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7d57-bdbd-5018af45b022" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-72af-aa2d-1967e7ff3d53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-72af-aa2d-1967e7ff3d53_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-72af-aa2d-1967e7ff3d53" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-72af-aa2d-1967e7ff3d53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7862-93c9-ad430523318f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-72af-aa2d-1967e7ff3d53" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7862-93c9-ad430523318f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_01a01620-5861-7ae5-9f0b-fcf2f9aa0c1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7862-93c9-ad430523318f" xlink:to="loc_us-gaap_SecuredDebtMember_01a01620-5861-7ae5-9f0b-fcf2f9aa0c1f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_01a01620-5861-727d-b377-95ea57098bae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7862-93c9-ad430523318f" xlink:to="loc_us-gaap_LineOfCreditMember_01a01620-5861-727d-b377-95ea57098bae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7e98-83c8-0f71a22e6d39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7862-93c9-ad430523318f" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7e98-83c8-0f71a22e6d39" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70ed-924d-1b3ecb35bc1f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7d57-bdbd-5018af45b022" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70ed-924d-1b3ecb35bc1f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-70ed-924d-1b3ecb35bc1f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70ed-924d-1b3ecb35bc1f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-70ed-924d-1b3ecb35bc1f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70ed-924d-1b3ecb35bc1f" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsMember_01a01620-5861-76c3-9b6f-b0a55d215bd7" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_SecuritizationTrustsMember_01a01620-5861-76c3-9b6f-b0a55d215bd7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GoldmanNMSFacilityMember_01a01620-5861-75ca-a310-29829c0dd8d0" xlink:href="newt-20260930.xsd#newt_GoldmanNMSFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_GoldmanNMSFacilityMember_01a01620-5861-75ca-a310-29829c0dd8d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-70ae-96d3-6dcf4d82d82a" xlink:href="newt-20260930.xsd#newt_CapitalOneFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-70ae-96d3-6dcf4d82d82a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-70f2-8b65-475a8b288a11" xlink:href="newt-20260930.xsd#newt_SPVIIDeutscheBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-70f2-8b65-475a8b288a11" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIIIOneFloridaBankFacilityMember_01a01620-5861-763d-91f3-0927179135ee" xlink:href="newt-20260930.xsd#newt_SPVIIIOneFloridaBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_SPVIIIOneFloridaBankFacilityMember_01a01620-5861-763d-91f3-0927179135ee" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIVD2FacilityMember_01a01620-5861-76a8-915e-007069b1c06b" xlink:href="newt-20260930.xsd#newt_SPVIVD2FacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_SPVIVD2FacilityMember_01a01620-5861-76a8-915e-007069b1c06b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FederalHomeLoanBankAdvancesMember_01a01620-5861-732b-8f65-20622ad54ecc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FederalHomeLoanBankAdvancesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_us-gaap_FederalHomeLoanBankAdvancesMember_01a01620-5861-732b-8f65-20622ad54ecc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-5861-779e-8aa4-4d374f411f08" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A2026NotesMember_01a01620-5861-779e-8aa4-4d374f411f08" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2027NotesMember_01a01620-5861-75ee-890d-bef364c9b0b8" xlink:href="newt-20260930.xsd#newt_A2027NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A2027NotesMember_01a01620-5861-75ee-890d-bef364c9b0b8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2028NotesMember_01a01620-5861-7b41-a3a3-e89a5934446b" xlink:href="newt-20260930.xsd#newt_A2028NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A2028NotesMember_01a01620-5861-7b41-a3a3-e89a5934446b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a01620-5861-7871-b4e8-ac31dc2abede" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A20298.50NotesMember_01a01620-5861-7871-b4e8-ac31dc2abede" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.625NotesMember_01a01620-5861-7eac-9e80-76a15b0d33ca" xlink:href="newt-20260930.xsd#newt_A20298.625NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A20298.625NotesMember_01a01620-5861-7eac-9e80-76a15b0d33ca" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20308.375NotesMember_01a01620-5861-7581-bb4a-1d565c367086" xlink:href="newt-20260930.xsd#newt_A20308.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A20308.375NotesMember_01a01620-5861-7581-bb4a-1d565c367086" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-5861-72ef-85ed-75fafc81cd17" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A20318.50NotesMember_01a01620-5861-72ef-85ed-75fafc81cd17" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20338.375NotesMember_01a01620-5861-7e2f-82fe-5fed4d2c72b8" xlink:href="newt-20260930.xsd#newt_A20338.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7576-8d7f-24d1ead50ba3" xlink:to="loc_newt_A20338.375NotesMember_01a01620-5861-7e2f-82fe-5fed4d2c72b8" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_01a01620-5861-785c-bc72-dac71e1debb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7d57-bdbd-5018af45b022" xlink:to="loc_us-gaap_CreditFacilityAxis_01a01620-5861-785c-bc72-dac71e1debb4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a01620-5861-785c-bc72-dac71e1debb4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_01a01620-5861-785c-bc72-dac71e1debb4" xlink:to="loc_us-gaap_CreditFacilityDomain_01a01620-5861-785c-bc72-dac71e1debb4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a01620-5861-76d8-8f89-8c7298393002" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_01a01620-5861-785c-bc72-dac71e1debb4" xlink:to="loc_us-gaap_CreditFacilityDomain_01a01620-5861-76d8-8f89-8c7298393002" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CapitalOneSP1Member_01a01620-5861-7b4d-aff7-ea9b846bc0e6" xlink:href="newt-20260930.xsd#newt_CapitalOneSP1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a01620-5861-76d8-8f89-8c7298393002" xlink:to="loc_newt_CapitalOneSP1Member_01a01620-5861-7b4d-aff7-ea9b846bc0e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_01a01620-5861-73b8-8e5a-6a53c980f6a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_01a01620-5861-73b8-8e5a-6a53c980f6a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a01620-5861-72f9-8727-49d50a7ecb31" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a01620-5861-72f9-8727-49d50a7ecb31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentMaximumBorrowingCapacityAmountOutstanding_01a01620-5861-7e16-b10c-0041d37303ad" xlink:href="newt-20260930.xsd#newt_DebtInstrumentMaximumBorrowingCapacityAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_newt_DebtInstrumentMaximumBorrowingCapacityAmountOutstanding_01a01620-5861-7e16-b10c-0041d37303ad" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_01a01620-5861-77b7-962d-447e8b241c00" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_us-gaap_LongTermDebt_01a01620-5861-77b7-962d-447e8b241c00" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LongTermLineOfCreditNetOfDeferredFinancingCosts_01a01620-5861-705b-9a6d-adaac534417f" xlink:href="newt-20260930.xsd#newt_LongTermLineOfCreditNetOfDeferredFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_newt_LongTermLineOfCreditNetOfDeferredFinancingCosts_01a01620-5861-705b-9a6d-adaac534417f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-7586-9555-ce6da90536a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-78d8-b5dc-a104a215b011" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-7586-9555-ce6da90536a4" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BORROWINGSOutstandingBorrowingsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BORROWINGSOutstandingBorrowingsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BORROWINGSOutstandingBorrowingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a01620-5861-749b-ac5f-d5fd49a083f0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtInstrumentTable_01a01620-5861-749b-ac5f-d5fd49a083f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70f2-87c0-675a750dc835" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-749b-ac5f-d5fd49a083f0" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70f2-87c0-675a750dc835" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-70f2-87c0-675a750dc835_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70f2-87c0-675a750dc835" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-70f2-87c0-675a750dc835_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-70f2-87c0-675a750dc835" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritizationTrustsMember_01a01620-5861-73b1-8f5b-1d0dd3236a1b" xlink:href="newt-20260930.xsd#newt_SecuritizationTrustsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_SecuritizationTrustsMember_01a01620-5861-73b1-8f5b-1d0dd3236a1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_GoldmanNMSFacilityMember_01a01620-5861-7787-a27d-dd92cb5badbe" xlink:href="newt-20260930.xsd#newt_GoldmanNMSFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_GoldmanNMSFacilityMember_01a01620-5861-7787-a27d-dd92cb5badbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-7e1f-8e9f-f06198ed11ce" xlink:href="newt-20260930.xsd#newt_CapitalOneFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-7e1f-8e9f-f06198ed11ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-7d51-bd88-c8c87a917c41" xlink:href="newt-20260930.xsd#newt_SPVIIDeutscheBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-7d51-bd88-c8c87a917c41" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIIIOneFloridaBankFacilityMember_01a01620-5861-7de2-8e64-f6e0ce7866bf" xlink:href="newt-20260930.xsd#newt_SPVIIIOneFloridaBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_SPVIIIOneFloridaBankFacilityMember_01a01620-5861-7de2-8e64-f6e0ce7866bf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIVD2FacilityMember_01a01620-5861-74df-803f-b462749a7d22" xlink:href="newt-20260930.xsd#newt_SPVIVD2FacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_SPVIVD2FacilityMember_01a01620-5861-74df-803f-b462749a7d22" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-5861-73c1-ac8c-3921a2d791b4" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A2026NotesMember_01a01620-5861-73c1-ac8c-3921a2d791b4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2027NotesMember_01a01620-5861-78cb-a88c-00e4a39b42a7" xlink:href="newt-20260930.xsd#newt_A2027NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A2027NotesMember_01a01620-5861-78cb-a88c-00e4a39b42a7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2028NotesMember_01a01620-5861-7055-9e65-f8f2f443a4c2" xlink:href="newt-20260930.xsd#newt_A2028NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A2028NotesMember_01a01620-5861-7055-9e65-f8f2f443a4c2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a01620-5861-7cbe-b811-4bece6dcef79" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20298.50NotesMember_01a01620-5861-7cbe-b811-4bece6dcef79" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.625NotesMember_01a01620-5861-7093-bf0b-7c72ca96e62d" xlink:href="newt-20260930.xsd#newt_A20298.625NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20298.625NotesMember_01a01620-5861-7093-bf0b-7c72ca96e62d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20308.375NotesMember_01a01620-5861-7c8b-b29e-30e9ac458891" xlink:href="newt-20260930.xsd#newt_A20308.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20308.375NotesMember_01a01620-5861-7c8b-b29e-30e9ac458891" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-5861-7888-a29c-0edd1afd9453" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20318.50NotesMember_01a01620-5861-7888-a29c-0edd1afd9453" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20338.375NotesMember_01a01620-5861-7a67-bbef-7ff39cf5de86" xlink:href="newt-20260930.xsd#newt_A20338.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20338.375NotesMember_01a01620-5861-7a67-bbef-7ff39cf5de86" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20258125NotesMember_01a01620-5861-7b66-94d2-2d93cbf964b3" xlink:href="newt-20260930.xsd#newt_A20258125NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-73ef-95bd-f95eebdd579e" xlink:to="loc_newt_A20258125NotesMember_01a01620-5861-7b66-94d2-2d93cbf964b3" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-7c4f-b601-a7f954271282" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-749b-ac5f-d5fd49a083f0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-7c4f-b601-a7f954271282" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7c4f-b601-a7f954271282_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-7c4f-b601-a7f954271282" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7c4f-b601-a7f954271282_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f53-8e73-05c477f8494a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-7c4f-b601-a7f954271282" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f53-8e73-05c477f8494a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_01a01620-5861-7ced-9b38-e39c70d0697c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f53-8e73-05c477f8494a" xlink:to="loc_us-gaap_SecuredDebtMember_01a01620-5861-7ced-9b38-e39c70d0697c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_01a01620-5861-7576-b2f1-03156cce02ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f53-8e73-05c477f8494a" xlink:to="loc_us-gaap_LineOfCreditMember_01a01620-5861-7576-b2f1-03156cce02ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7fcc-a84d-c201e12466da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f53-8e73-05c477f8494a" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5861-7fcc-a84d-c201e12466da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-5861-7502-8ff5-a555ae98d598" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-5861-7502-8ff5-a555ae98d598" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_01a01620-5861-7aea-ac1e-c6ca6e8af89f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_01a01620-5861-7aea-ac1e-c6ca6e8af89f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LongTermDebtNetOfDeferredFinancingCosts_01a01620-5861-7c26-b7c6-f52413edce95" xlink:href="newt-20260930.xsd#newt_LongTermDebtNetOfDeferredFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_newt_LongTermDebtNetOfDeferredFinancingCosts_01a01620-5861-7c26-b7c6-f52413edce95" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-7a58-9abf-24f2cd758241" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-7a58-9abf-24f2cd758241" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a19e0c-5256-788b-b619-48c6bc427c0d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a19e0c-5256-788b-b619-48c6bc427c0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a01620-5861-7828-bf7f-e90e61601560" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a01620-5861-7828-bf7f-e90e61601560" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-5861-7bc8-90c3-1e1a84d79b4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfMediumTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7eba-aba1-d993df4a75bc" xlink:to="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-5861-7bc8-90c3-1e1a84d79b4d" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BORROWINGSNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BORROWINGSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BORROWINGSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7073-b54f-2d545eb27231" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7073-b54f-2d545eb27231" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7073-b54f-2d545eb27231_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7073-b54f-2d545eb27231" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7073-b54f-2d545eb27231_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5861-7073-b54f-2d545eb27231" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20338.375NotesMember_01a01620-5861-7fb7-9f37-039f10245c1b" xlink:href="newt-20260930.xsd#newt_A20338.375NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_A20338.375NotesMember_01a01620-5861-7fb7-9f37-039f10245c1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-5861-7f6d-a9a4-02b6c73ae11f" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_A20318.50NotesMember_01a01620-5861-7f6d-a9a4-02b6c73ae11f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2026NotesMember_01a01620-5861-71e3-a17f-6c99399b33f3" xlink:href="newt-20260930.xsd#newt_A2026NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_A2026NotesMember_01a01620-5861-71e3-a17f-6c99399b33f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-7678-be6d-6d3cb1608073" xlink:href="newt-20260930.xsd#newt_CapitalOneFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_CapitalOneFacilitiesMember_01a01620-5861-7678-be6d-6d3cb1608073" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-79ec-a043-a042f2c1c998" xlink:href="newt-20260930.xsd#newt_SPVIIDeutscheBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_SPVIIDeutscheBankFacilityMember_01a01620-5861-79ec-a043-a042f2c1c998" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVOneFloridaBankFacilityMember_01a01620-5861-7de2-8e57-84d5cbca84a9" xlink:href="newt-20260930.xsd#newt_SPVOneFloridaBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_SPVOneFloridaBankFacilityMember_01a01620-5861-7de2-8e57-84d5cbca84a9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SPVIVD2FacilityMember_01a01620-5861-7207-bf42-ded3315e8769" xlink:href="newt-20260930.xsd#newt_SPVIVD2FacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5861-7a6e-abae-7c1bc0071e8a" xlink:to="loc_newt_SPVIVD2FacilityMember_01a01620-5861-7207-bf42-ded3315e8769" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-70ba-bb7c-1363d95a426b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-70ba-bb7c-1363d95a426b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-70ba-bb7c-1363d95a426b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-70ba-bb7c-1363d95a426b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-70ba-bb7c-1363d95a426b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f2f-a05e-0a5c77208d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-70ba-bb7c-1363d95a426b" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f2f-a05e-0a5c77208d7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5861-76e0-9a6f-84e6d35e098d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f2f-a05e-0a5c77208d7b" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5861-76e0-9a6f-84e6d35e098d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_01a01620-5861-793a-b4a3-eb8d412b29d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7f2f-a05e-0a5c77208d7b" xlink:to="loc_us-gaap_LineOfCreditMember_01a01620-5861-793a-b4a3-eb8d412b29d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_01a01620-5861-7e1f-a635-b5bd8ca08d67" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:to="loc_us-gaap_CreditFacilityAxis_01a01620-5861-7e1f-a635-b5bd8ca08d67" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a01620-5861-7e1f-a635-b5bd8ca08d67_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_01a01620-5861-7e1f-a635-b5bd8ca08d67" xlink:to="loc_us-gaap_CreditFacilityDomain_01a01620-5861-7e1f-a635-b5bd8ca08d67_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_01a01620-5861-78c3-9b27-f3a38c37d1e2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_01a01620-5861-7e1f-a635-b5bd8ca08d67" xlink:to="loc_us-gaap_CreditFacilityDomain_01a01620-5861-78c3-9b27-f3a38c37d1e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CapitalOneSP1Member_01a01620-5861-7fce-8585-d66260184a3b" xlink:href="newt-20260930.xsd#newt_CapitalOneSP1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_01a01620-5861-78c3-9b27-f3a38c37d1e2" xlink:to="loc_newt_CapitalOneSP1Member_01a01620-5861-7fce-8585-d66260184a3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_01a01620-5861-731b-915f-341c55ca4bd5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:to="loc_dei_LegalEntityAxis_01a01620-5861-731b-915f-341c55ca4bd5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-5861-731b-915f-341c55ca4bd5_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_01a01620-5861-731b-915f-341c55ca4bd5" xlink:to="loc_dei_EntityDomain_01a01620-5861-731b-915f-341c55ca4bd5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a01620-5861-7044-8627-4d7735105de3" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_01a01620-5861-731b-915f-341c55ca4bd5" xlink:to="loc_dei_EntityDomain_01a01620-5861-7044-8627-4d7735105de3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NewtekBusinessLendingLLCMember_01a01620-5861-7e53-9025-354ff046ee6f" xlink:href="newt-20260930.xsd#newt_NewtekBusinessLendingLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a01620-5861-7044-8627-4d7735105de3" xlink:to="loc_newt_NewtekBusinessLendingLLCMember_01a01620-5861-7e53-9025-354ff046ee6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsByNatureAxis_01a01620-5861-775c-a183-1029fb56d26e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsByNatureAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7f63-90ee-7fda4f01dcc2" xlink:to="loc_us-gaap_GuaranteeObligationsByNatureAxis_01a01620-5861-775c-a183-1029fb56d26e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_01a01620-5861-775c-a183-1029fb56d26e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_01a01620-5861-775c-a183-1029fb56d26e" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_01a01620-5861-775c-a183-1029fb56d26e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsNatureDomain_01a01620-5861-72af-a42f-f45cbf1d9211" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GuaranteeObligationsByNatureAxis_01a01620-5861-775c-a183-1029fb56d26e" xlink:to="loc_us-gaap_GuaranteeObligationsNatureDomain_01a01620-5861-72af-a42f-f45cbf1d9211" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentGuaranteeMember_01a01620-5861-7bda-a63b-d9897304837a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentGuaranteeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GuaranteeObligationsNatureDomain_01a01620-5861-72af-a42f-f45cbf1d9211" xlink:to="loc_us-gaap_PaymentGuaranteeMember_01a01620-5861-7bda-a63b-d9897304837a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-5861-798e-8db0-7c60a85221b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a01620-5861-798e-8db0-7c60a85221b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-784f-b3c6-5fb307c9cc50" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5861-784f-b3c6-5fb307c9cc50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfMediumTermNotes_01a01620-5861-71cd-bb4f-0f6f26d81528" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfMediumTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfMediumTermNotes_01a01620-5861-71cd-bb4f-0f6f26d81528" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a01620-5861-7612-9cd7-2792c429cba9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a01620-5861-7612-9cd7-2792c429cba9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-5861-7f0a-8957-0ca9662e8c70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RepaymentsOfMediumTermNotes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_RepaymentsOfMediumTermNotes_01a01620-5861-7f0a-8957-0ca9662e8c70" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a01620-5861-7e12-abc3-a59eb77c925c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_01a01620-5861-7e12-abc3-a59eb77c925c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GuaranteeObligationsMaximumExposure_01a01620-5861-7c0f-831f-5880d134d204" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GuaranteeObligationsMaximumExposure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7de5-9bb2-bec3f2faf25c" xlink:to="loc_us-gaap_GuaranteeObligationsMaximumExposure_01a01620-5861-7c0f-831f-5880d134d204" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BORROWINGSInterestExpenseDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BORROWINGSInterestExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BORROWINGSInterestExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7bdf-ac63-7c22a9ba86fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7730-a764-5d4dfff72f9a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7bdf-ac63-7c22a9ba86fb" xlink:to="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7730-a764-5d4dfff72f9a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-769e-9e94-64615818473e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_01a01620-5861-7730-a764-5d4dfff72f9a" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-769e-9e94-64615818473e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-769e-9e94-64615818473e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-769e-9e94-64615818473e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-769e-9e94-64615818473e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7231-8cae-579a0e076507" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5861-769e-9e94-64615818473e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7231-8cae-579a0e076507" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5861-757b-b2af-b41fd4ae97a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5861-7231-8cae-579a0e076507" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5861-757b-b2af-b41fd4ae97a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_01a01620-5861-7204-bd88-90b6f3496425" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_01a01620-5861-7bdf-ac63-7c22a9ba86fb" xlink:to="loc_us-gaap_InterestExpenseDebt_01a01620-5861-7204-bd88-90b6f3496425" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/DERIVATIVEINSTRUMENTSDerivativesOutstandingDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#DERIVATIVEINSTRUMENTSDerivativesOutstandingDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/DERIVATIVEINSTRUMENTSDerivativesOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-736c-a762-a849c26e4e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-736c-a762-a849c26e4e6d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-764f-a200-05e143c20ba7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-736c-a762-a849c26e4e6d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-764f-a200-05e143c20ba7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-764f-a200-05e143c20ba7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-764f-a200-05e143c20ba7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-764f-a200-05e143c20ba7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7c6e-8404-8bb79332dd34" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-764f-a200-05e143c20ba7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7c6e-8404-8bb79332dd34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeFutureMember_01a01620-5861-77af-bc07-e452a6e4eb6a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeFutureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7c6e-8404-8bb79332dd34" xlink:to="loc_us-gaap_ForeignExchangeFutureMember_01a01620-5861-77af-bc07-e452a6e4eb6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PositionAxis_01a01620-5861-7002-8a4e-72cfac780d6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PositionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-736c-a762-a849c26e4e6d" xlink:to="loc_us-gaap_PositionAxis_01a01620-5861-7002-8a4e-72cfac780d6b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PositionDomain_01a01620-5861-7002-8a4e-72cfac780d6b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PositionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PositionAxis_01a01620-5861-7002-8a4e-72cfac780d6b" xlink:to="loc_us-gaap_PositionDomain_01a01620-5861-7002-8a4e-72cfac780d6b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PositionDomain_01a01620-5861-75c1-83b4-942777770308" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PositionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PositionAxis_01a01620-5861-7002-8a4e-72cfac780d6b" xlink:to="loc_us-gaap_PositionDomain_01a01620-5861-75c1-83b4-942777770308" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortMember_01a01620-5861-7ee8-aea9-f705d6038b95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShortMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PositionDomain_01a01620-5861-75c1-83b4-942777770308" xlink:to="loc_us-gaap_ShortMember_01a01620-5861-7ee8-aea9-f705d6038b95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_01a01620-5861-7615-99bf-973d55b2b99d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:to="loc_us-gaap_DerivativeNotionalAmount_01a01620-5861-7615-99bf-973d55b2b99d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_01a01620-5861-773b-83b5-7343af4d9a6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:to="loc_us-gaap_DerivativeAssets_01a01620-5861-773b-83b5-7343af4d9a6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_01a01620-5861-7541-ab6a-0fe0f65ddccc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:to="loc_us-gaap_DerivativeLiabilities_01a01620-5861-7541-ab6a-0fe0f65ddccc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeRemainingMaturity1_01a01620-5861-7333-9a52-194e7d29b91c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeRemainingMaturity1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-7ca2-abbd-4027df5c46d2" xlink:to="loc_us-gaap_DerivativeRemainingMaturity1_01a01620-5861-7333-9a52-194e7d29b91c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/DERIVATIVEINSTRUMENTSGainsandLossesDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#DERIVATIVEINSTRUMENTSGainsandLossesDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/DERIVATIVEINSTRUMENTSGainsandLossesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-728a-8b85-e443744fe584" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-775a-b959-83eb0fac4559" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-728a-8b85-e443744fe584" xlink:to="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-775a-b959-83eb0fac4559" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-7fae-bb2f-750d9cd396a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresTable_01a01620-5861-775a-b959-83eb0fac4559" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-7fae-bb2f-750d9cd396a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7fae-bb2f-750d9cd396a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-7fae-bb2f-750d9cd396a3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7fae-bb2f-750d9cd396a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7b6e-909e-405a64f23873" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_01a01620-5861-7fae-bb2f-750d9cd396a3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7b6e-909e-405a64f23873" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeFutureMember_01a01620-5861-7556-9003-61ca857c7ee9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeFutureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_01a01620-5861-7b6e-909e-405a64f23873" xlink:to="loc_us-gaap_ForeignExchangeFutureMember_01a01620-5861-7556-9003-61ca857c7ee9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_01a01620-5861-77a0-b53c-0a5dd5f93100" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-728a-8b85-e443744fe584" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_01a01620-5861-77a0-b53c-0a5dd5f93100" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfDerivatives_01a01620-5861-7c5c-93d4-dbff94f7948f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnSaleOfDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosuresLineItems_01a01620-5861-728a-8b85-e443744fe584" xlink:to="loc_us-gaap_GainLossOnSaleOfDerivatives_01a01620-5861-7c5c-93d4-dbff94f7948f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/COMMITMENTSANDCONTINGENCIESUnfundedCommitmentsDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#COMMITMENTSANDCONTINGENCIESUnfundedCommitmentsDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/COMMITMENTSANDCONTINGENCIESUnfundedCommitmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsLineItems_01a01620-5909-76f1-be26-56727294302b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsTable_01a01620-5909-741a-a95a-a2cd5e72b8ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_01a01620-5909-76f1-be26-56727294302b" xlink:to="loc_us-gaap_OtherCommitmentsTable_01a01620-5909-741a-a95a-a2cd5e72b8ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_01a01620-5909-720c-92a3-b57a44e81f08" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OtherCommitmentsTable_01a01620-5909-741a-a95a-a2cd5e72b8ab" xlink:to="loc_us-gaap_FinancialInstrumentAxis_01a01620-5909-720c-92a3-b57a44e81f08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5909-720c-92a3-b57a44e81f08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5909-720c-92a3-b57a44e81f08" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5909-720c-92a3-b57a44e81f08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5909-7059-a23f-f9fae74a31ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_01a01620-5909-720c-92a3-b57a44e81f08" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5909-7059-a23f-f9fae74a31ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsToExtendCreditMember_01a01620-5909-735d-843c-39c3453d094d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommitmentsToExtendCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_01a01620-5909-7059-a23f-f9fae74a31ce" xlink:to="loc_us-gaap_CommitmentsToExtendCreditMember_01a01620-5909-735d-843c-39c3453d094d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SBA7aLoanMember_01a01620-5909-7b9e-9c61-5de62968adb0" xlink:href="newt-20260930.xsd#newt_SBA7aLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommitmentsToExtendCreditMember_01a01620-5909-735d-843c-39c3453d094d" xlink:to="loc_newt_SBA7aLoanMember_01a01620-5909-7b9e-9c61-5de62968adb0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A504LoanMember_01a01620-5909-7ee6-a7b0-8af7de690c4b" xlink:href="newt-20260930.xsd#newt_A504LoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommitmentsToExtendCreditMember_01a01620-5909-735d-843c-39c3453d094d" xlink:to="loc_newt_A504LoanMember_01a01620-5909-7ee6-a7b0-8af7de690c4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_CommercialAndIndustrialLoansMember_01a01620-5909-7a55-8aea-c28b6e3557a3" xlink:href="newt-20260930.xsd#newt_CommercialAndIndustrialLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CommitmentsToExtendCreditMember_01a01620-5909-735d-843c-39c3453d094d" xlink:to="loc_newt_CommercialAndIndustrialLoansMember_01a01620-5909-7a55-8aea-c28b6e3557a3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_01a01620-5909-762b-a35e-6aae96acd216" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_01a01620-5909-76f1-be26-56727294302b" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_01a01620-5909-762b-a35e-6aae96acd216" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability_01a01620-5909-77a2-97bf-42004e372bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsLineItems_01a01620-5909-76f1-be26-56727294302b" xlink:to="loc_us-gaap_FairValueDisclosureOffbalanceSheetRisksAmountLiability_01a01620-5909-77a2-97bf-42004e372bbd" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SHAREHOLDERSEQUITYNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SHAREHOLDERSEQUITYNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SHAREHOLDERSEQUITYNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7c28-977c-f636d1a93997" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7c28-977c-f636d1a93997" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7c28-977c-f636d1a93997_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7c28-977c-f636d1a93997" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7c28-977c-f636d1a93997_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7612-9669-ca1d3b96f96e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7c28-977c-f636d1a93997" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7612-9669-ca1d3b96f96e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2023ATMEquityDistributionMember_01a01620-5909-70f4-872e-d0730a88174f" xlink:href="newt-20260930.xsd#newt_A2023ATMEquityDistributionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7612-9669-ca1d3b96f96e" xlink:to="loc_newt_A2023ATMEquityDistributionMember_01a01620-5909-70f4-872e-d0730a88174f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7e07-a496-a6f4d5736e36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7e07-a496-a6f4d5736e36" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-5909-7e07-a496-a6f4d5736e36_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7e07-a496-a6f4d5736e36" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-5909-7e07-a496-a6f4d5736e36_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-5909-793d-b561-0773b271353b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7e07-a496-a6f4d5736e36" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-5909-793d-b561-0773b271353b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SeriesAConvertiblePreferredStockMember_01a01620-5909-7cb8-bc5b-b061cef22c68" xlink:href="newt-20260930.xsd#newt_SeriesAConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-5909-793d-b561-0773b271353b" xlink:to="loc_newt_SeriesAConvertiblePreferredStockMember_01a01620-5909-7cb8-bc5b-b061cef22c68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DepositorySharesMember_01a01620-5909-7070-b301-b50022dd6220" xlink:href="newt-20260930.xsd#newt_DepositorySharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-5909-793d-b561-0773b271353b" xlink:to="loc_newt_DepositorySharesMember_01a01620-5909-7070-b301-b50022dd6220" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_01a01620-5909-7a41-b79d-3a2d388df4c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-5909-793d-b561-0773b271353b" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_01a01620-5909-7a41-b79d-3a2d388df4c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a01620-5909-7037-b5b7-2183bf665181" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a01620-5909-7037-b5b7-2183bf665181" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7037-b5b7-2183bf665181_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5909-7037-b5b7-2183bf665181" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7037-b5b7-2183bf665181_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7d74-8792-baa616a09432" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a01620-5909-7037-b5b7-2183bf665181" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7d74-8792-baa616a09432" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TheNotesMember_01a01620-5909-700a-8ffa-89e0540ec369" xlink:href="newt-20260930.xsd#newt_TheNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7d74-8792-baa616a09432" xlink:to="loc_newt_TheNotesMember_01a01620-5909-700a-8ffa-89e0540ec369" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.50NotesMember_01a01620-5909-7529-835c-f808c82757b2" xlink:href="newt-20260930.xsd#newt_A20298.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_TheNotesMember_01a01620-5909-700a-8ffa-89e0540ec369" xlink:to="loc_newt_A20298.50NotesMember_01a01620-5909-7529-835c-f808c82757b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20298.625NotesMember_01a01620-5909-7202-a93e-7086a3b47ace" xlink:href="newt-20260930.xsd#newt_A20298.625NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_TheNotesMember_01a01620-5909-700a-8ffa-89e0540ec369" xlink:to="loc_newt_A20298.625NotesMember_01a01620-5909-7202-a93e-7086a3b47ace" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A20318.50NotesMember_01a01620-5909-7954-8c38-4cd0f8f6eb80" xlink:href="newt-20260930.xsd#newt_A20318.50NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_TheNotesMember_01a01620-5909-700a-8ffa-89e0540ec369" xlink:to="loc_newt_A20318.50NotesMember_01a01620-5909-7954-8c38-4cd0f8f6eb80" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2028And2029NotesMember_01a01620-5909-7d68-8025-9cc5d324bddb" xlink:href="newt-20260930.xsd#newt_A2028And2029NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a01620-5909-7d74-8792-baa616a09432" xlink:to="loc_newt_A2028And2029NotesMember_01a01620-5909-7d68-8025-9cc5d324bddb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5909-79f9-808d-168a9091c1ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7699-8e13-fa57723807d4" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5909-79f9-808d-168a9091c1ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5909-79f9-808d-168a9091c1ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5909-79f9-808d-168a9091c1ae" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5909-79f9-808d-168a9091c1ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5909-77c9-958f-fa6489e39a41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a01620-5909-79f9-808d-168a9091c1ae" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5909-77c9-958f-fa6489e39a41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MediumTermNotesMember_01a01620-5909-733f-b5c4-e4f9383d039e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MediumTermNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a01620-5909-77c9-958f-fa6489e39a41" xlink:to="loc_us-gaap_MediumTermNotesMember_01a01620-5909-733f-b5c4-e4f9383d039e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01a01620-5909-7057-ad0e-ed3cd462bba2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01a01620-5909-7057-ad0e-ed3cd462bba2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_01a01620-5909-7fdc-8100-b50755bada48" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_01a01620-5909-7fdc-8100-b50755bada48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_01a01620-5909-7755-8d3f-677e5dde44d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_01a01620-5909-7755-8d3f-677e5dde44d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssuedPricePerShare_01a01620-5909-7ae7-9504-6de9a81100ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharesIssuedPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_SharesIssuedPricePerShare_01a01620-5909-7ae7-9504-6de9a81100ae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockConvertibleSharesIssuable_01a01620-5909-7363-9419-5d25f1b933ce" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockConvertibleSharesIssuable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_PreferredStockConvertibleSharesIssuable_01a01620-5909-7363-9419-5d25f1b933ce" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement_01a01620-5909-7572-baea-9162ee823965" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPurchaseAndExchangeAgreement_01a01620-5909-7572-baea-9162ee823965" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement_01a01620-5909-7a2e-924f-091d780e894d" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_StockIssuedDuringPeriodValueNewIssuesPurchaseAndExchangeAgreement_01a01620-5909-7a2e-924f-091d780e894d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodValueNewIssuesCashValue_01a01620-5909-758e-871c-f529d3d7b271" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodValueNewIssuesCashValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_StockIssuedDuringPeriodValueNewIssuesCashValue_01a01620-5909-758e-871c-f529d3d7b271" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PurchaseAndExchangeAgreementSharesExchanged_01a01620-5909-774d-8a0b-c3404fd94022" xlink:href="newt-20260930.xsd#newt_PurchaseAndExchangeAgreementSharesExchanged"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_PurchaseAndExchangeAgreementSharesExchanged_01a01620-5909-774d-8a0b-c3404fd94022" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PurchaseAndExchangeAgreementSharesExchangedRestrictionPeriod_01a01620-5909-7642-b140-f8bd3180829c" xlink:href="newt-20260930.xsd#newt_PurchaseAndExchangeAgreementSharesExchangedRestrictionPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_PurchaseAndExchangeAgreementSharesExchangedRestrictionPeriod_01a01620-5909-7642-b140-f8bd3180829c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPercentageInterestInEachShare_01a01620-5909-7527-a17b-036ae7eaf82f" xlink:href="newt-20260930.xsd#newt_StockIssuedDuringPeriodSharesNewIssuesPercentageInterestInEachShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_StockIssuedDuringPeriodSharesNewIssuesPercentageInterestInEachShare_01a01620-5909-7527-a17b-036ae7eaf82f" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_01a01620-5909-7ade-9904-9b36413e0994" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_PreferredStockDividendRatePercentage_01a01620-5909-7ade-9904-9b36413e0994" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockLiquidationPreference_01a01620-5909-759b-ae76-c6ba5a1c1762" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockLiquidationPreference"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_PreferredStockLiquidationPreference_01a01620-5909-759b-ae76-c6ba5a1c1762" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PreferredStockLiquidationPreferencePerDepositaryShare_01a01620-5909-706e-a722-ef30d5ddf81a" xlink:href="newt-20260930.xsd#newt_PreferredStockLiquidationPreferencePerDepositaryShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_PreferredStockLiquidationPreferencePerDepositaryShare_01a01620-5909-706e-a722-ef30d5ddf81a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_01a01620-5909-7fb7-861d-a6c9e5e92fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock_01a01620-5909-7fb7-861d-a6c9e5e92fd3" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightUnissued_01a01620-5909-7b09-8fde-8cdb0f399364" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightUnissued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_ClassOfWarrantOrRightUnissued_01a01620-5909-7b09-8fde-8cdb0f399364" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_01a01620-5909-770d-a09f-81d2bf81fb6d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_01a01620-5909-770d-a09f-81d2bf81fb6d" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_01a01620-5909-713d-a8f3-46501e902116" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_01a01620-5909-713d-a8f3-46501e902116" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SaleOfStockNumberOfSharesAuthorizedForSale_01a01620-5909-7de4-9b2e-d6ca45c4853f" xlink:href="newt-20260930.xsd#newt_SaleOfStockNumberOfSharesAuthorizedForSale"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_SaleOfStockNumberOfSharesAuthorizedForSale_01a01620-5909-7de4-9b2e-d6ca45c4853f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritiesDistributionAgreementValueOfPrincipalAmountOffered_01a01620-5909-7142-b8ef-242c899cf6af" xlink:href="newt-20260930.xsd#newt_SecuritiesDistributionAgreementValueOfPrincipalAmountOffered"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_SecuritiesDistributionAgreementValueOfPrincipalAmountOffered_01a01620-5909-7142-b8ef-242c899cf6af" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5909-7ee2-95c4-ab3ad5dc616f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_01a01620-5909-7ee2-95c4-ab3ad5dc616f" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockDividendRatePercentage_01a01620-5909-792a-b453-e5d248fced9d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockDividendRatePercentage"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritiesDistributionAgreementSharesOfNotesSold_01a01620-5909-7034-bdae-b5f9dec53814" xlink:href="newt-20260930.xsd#newt_SecuritiesDistributionAgreementSharesOfNotesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_SecuritiesDistributionAgreementSharesOfNotesSold_01a01620-5909-7034-bdae-b5f9dec53814" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SecuritiesDistributionAgreementProceedsFromNotesSold_01a01620-5909-7441-9312-a48d4b3a2d2a" xlink:href="newt-20260930.xsd#newt_SecuritiesDistributionAgreementProceedsFromNotesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_SecuritiesDistributionAgreementProceedsFromNotesSold_01a01620-5909-7441-9312-a48d4b3a2d2a" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_01a01620-5909-7644-89e4-e5eb1b6abf81" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_srt_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased_01a01620-5909-7644-89e4-e5eb1b6abf81" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_01a01620-5909-70ac-a036-b1e7edd7000d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockRepurchaseProgramPeriodInForce1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_01a01620-5909-70ac-a036-b1e7edd7000d" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ShareRepurchaseProgramPeriodInForceExtension_01a01620-5909-7593-87c1-9bd44675601a" xlink:href="newt-20260930.xsd#newt_ShareRepurchaseProgramPeriodInForceExtension"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_ShareRepurchaseProgramPeriodInForceExtension_01a01620-5909-7593-87c1-9bd44675601a" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRepurchaseAmount_01a01620-5909-7a03-a8b4-2ae0376a4c70" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRepurchaseAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_us-gaap_DebtInstrumentRepurchaseAmount_01a01620-5909-7a03-a8b4-2ae0376a4c70" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentRepurchasePeriod_01a01620-5909-7558-b99f-51a3b94fe45e" xlink:href="newt-20260930.xsd#newt_DebtInstrumentRepurchasePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_DebtInstrumentRepurchasePeriod_01a01620-5909-7558-b99f-51a3b94fe45e" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentRepurchaseAmountShares_01a0f338-b354-7383-97ca-f337f01e88a4" xlink:href="newt-20260930.xsd#newt_DebtInstrumentRepurchaseAmountShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7622-bb11-1d62c821e856" xlink:to="loc_newt_DebtInstrumentRepurchaseAmountShares_01a0f338-b354-7383-97ca-f337f01e88a4" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SHAREHOLDERSEQUITYATMEquityDistributionDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SHAREHOLDERSEQUITYATMEquityDistributionDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SHAREHOLDERSEQUITYATMEquityDistributionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-71e7-8a93-e473158c795d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:to="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-71e7-8a93-e473158c795d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7172-83cb-2d81e0cd38ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-71e7-8a93-e473158c795d" xlink:to="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7172-83cb-2d81e0cd38ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7172-83cb-2d81e0cd38ed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7172-83cb-2d81e0cd38ed" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7172-83cb-2d81e0cd38ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7a74-af5a-e4dbc83b3138" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNameOfTransactionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsidiarySaleOfStockAxis_01a01620-5909-7172-83cb-2d81e0cd38ed" xlink:to="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7a74-af5a-e4dbc83b3138" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2023ATMEquityDistributionMember_01a01620-5909-7585-bb99-09fbc64cb81d" xlink:href="newt-20260930.xsd#newt_A2023ATMEquityDistributionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SaleOfStockNameOfTransactionDomain_01a01620-5909-7a74-af5a-e4dbc83b3138" xlink:to="loc_newt_A2023ATMEquityDistributionMember_01a01620-5909-7585-bb99-09fbc64cb81d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_01a01620-5909-71f6-8d4d-41229daed8e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_01a01620-5909-71f6-8d4d-41229daed8e1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SaleOfStockWeightedAveragePricePerShare_01a01620-5909-7814-9549-ae82f2b75c0e" xlink:href="newt-20260930.xsd#newt_SaleOfStockWeightedAveragePricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:to="loc_newt_SaleOfStockWeightedAveragePricePerShare_01a01620-5909-7814-9549-ae82f2b75c0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_01a01620-5909-7bf5-81f2-e15a0dc288eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SaleOfStockConsiderationReceivedOnTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:to="loc_us-gaap_SaleOfStockConsiderationReceivedOnTransaction_01a01620-5909-7bf5-81f2-e15a0dc288eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a01620-5909-7d1a-989e-cd180f9b4c41" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-703e-bc4d-25e8bf0b971f" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a01620-5909-7d1a-989e-cd180f9b4c41" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SHAREHOLDERSEQUITYDividendsDeclaredandDistributedDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SHAREHOLDERSEQUITYDividendsDeclaredandDistributedDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SHAREHOLDERSEQUITYDividendsDeclaredandDistributedDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiarySaleOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7fdf-a63f-33e831629993" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:to="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7fdf-a63f-33e831629993" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a01620-5909-7627-bce7-330d7fd4da29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7fdf-a63f-33e831629993" xlink:to="loc_us-gaap_AwardTypeAxis_01a01620-5909-7627-bce7-330d7fd4da29" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7627-bce7-330d7fd4da29_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7627-bce7-330d7fd4da29" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7627-bce7-330d7fd4da29_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7768-8aae-e1924f2841f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7627-bce7-330d7fd4da29" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7768-8aae-e1924f2841f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnvestedRestrictedStockMember_01a01620-5909-75c8-8f6d-73449b01b004" xlink:href="newt-20260930.xsd#newt_UnvestedRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7768-8aae-e1924f2841f8" xlink:to="loc_newt_UnvestedRestrictedStockMember_01a01620-5909-75c8-8f6d-73449b01b004" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7067-9067-403826926688" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7fdf-a63f-33e831629993" xlink:to="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7067-9067-403826926688" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-5909-7067-9067-403826926688_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7067-9067-403826926688" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-5909-7067-9067-403826926688_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_01a01620-5909-712a-846a-e853872a20e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_01a01620-5909-7067-9067-403826926688" xlink:to="loc_us-gaap_ClassOfStockDomain_01a01620-5909-712a-846a-e853872a20e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SeriesAConvertiblePreferredStockMember_01a01620-5909-7860-b765-ba4f042257e9" xlink:href="newt-20260930.xsd#newt_SeriesAConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_01a01620-5909-712a-846a-e853872a20e8" xlink:to="loc_newt_SeriesAConvertiblePreferredStockMember_01a01620-5909-7860-b765-ba4f042257e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsidiaryOrEquityMethodInvesteeSaleOfStockBySubsidiaryOrEquityInvesteeTable_01a01620-5909-7fdf-a63f-33e831629993" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a0f33d-ae36-7e93-813f-a0a950704f7b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a0f33d-ae36-7fd9-ae46-11691e3ec3d6" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a0f33d-ae36-7e93-813f-a0a950704f7b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_01a0f33d-c7ac-7622-aa0d-70d06742bd4c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_01a0f33d-ae36-7e93-813f-a0a950704f7b" xlink:to="loc_us-gaap_SubsequentEventMember_01a0f33d-c7ac-7622-aa0d-70d06742bd4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_01a01620-5909-7214-9748-9f59444de8d8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyDistributionToShareholdersPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:to="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_01a01620-5909-7214-9748-9f59444de8d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDividendDistribution_01a01620-5909-7294-a44a-5c78691e0ce4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InvestmentCompanyDividendDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:to="loc_us-gaap_InvestmentCompanyDividendDistribution_01a01620-5909-7294-a44a-5c78691e0ce4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_01a01620-5909-719c-8a0a-564a324f48e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_01a01620-5909-719c-8a0a-564a324f48e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_01a01620-5909-71f9-b6a6-ff285f296bb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsidiarySaleOfStockLineItems_01a01620-5909-7d0a-aa30-110e7bfb9e7c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_01a01620-5909-71f9-b6a6-ff285f296bb2" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSNarrativeDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-74b3-aa10-db6c5b120044" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-74b3-aa10-db6c5b120044" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_01a01620-5909-7b27-a205-c5e5439247b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-74b3-aa10-db6c5b120044" xlink:to="loc_us-gaap_PlanNameAxis_01a01620-5909-7b27-a205-c5e5439247b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-7b27-a205-c5e5439247b2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7b27-a205-c5e5439247b2" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-7b27-a205-c5e5439247b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-7587-80bd-9a06a9f2544e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7b27-a205-c5e5439247b2" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-7587-80bd-9a06a9f2544e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-7d66-a271-3df7fb6b15da" xlink:href="newt-20260930.xsd#newt_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01a01620-5909-7587-80bd-9a06a9f2544e" xlink:to="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-7d66-a271-3df7fb6b15da" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a01620-5909-7398-94f3-322dd1c8b2b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a01620-5909-7398-94f3-322dd1c8b2b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_01a01620-5909-7d74-a02c-6c262ae99af6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumEmployeeSubscriptionRate_01a01620-5909-7d74-a02c-6c262ae99af6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumFairValueOfSharesToBePurchased_01a01620-5909-7e0f-91f9-d80d90965226" xlink:href="newt-20260930.xsd#newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumFairValueOfSharesToBePurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:to="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumFairValueOfSharesToBePurchased_01a01620-5909-7e0f-91f9-d80d90965226" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_01a01620-5909-79dd-bf01-d5dd84ce851f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-7060-aeb3-957c7b5a15ee" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardPurchasePriceOfCommonStockPercent_01a01620-5909-79dd-bf01-d5dd84ce851f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSRestrictedStockActivityDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSRestrictedStockActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-74e3-808b-bdaa38fb8b90" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-74e3-808b-bdaa38fb8b90" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a01620-5909-7523-988d-9de582cbc455" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-74e3-808b-bdaa38fb8b90" xlink:to="loc_us-gaap_AwardTypeAxis_01a01620-5909-7523-988d-9de582cbc455" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7523-988d-9de582cbc455_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7523-988d-9de582cbc455" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7523-988d-9de582cbc455_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7944-bff3-d7f8158f8466" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7523-988d-9de582cbc455" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7944-bff3-d7f8158f8466" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01a01620-5909-7040-91cd-16a3d5d4182f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7944-bff3-d7f8158f8466" xlink:to="loc_us-gaap_RestrictedStockMember_01a01620-5909-7040-91cd-16a3d5d4182f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_01a01620-5909-7cb3-a027-689509b1d137" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-74e3-808b-bdaa38fb8b90" xlink:to="loc_us-gaap_PlanNameAxis_01a01620-5909-7cb3-a027-689509b1d137" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-7cb3-a027-689509b1d137_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7cb3-a027-689509b1d137" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-7cb3-a027-689509b1d137_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-7009-9818-b659fb110157" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7cb3-a027-689509b1d137" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-7009-9818-b659fb110157" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2023And2015StockIncentivePlanMember_01a01620-5909-775d-bc27-506e8fb47481" xlink:href="newt-20260930.xsd#newt_A2023And2015StockIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01a01620-5909-7009-9818-b659fb110157" xlink:to="loc_newt_A2023And2015StockIncentivePlanMember_01a01620-5909-775d-bc27-506e8fb47481" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2023StockIncentivePlanMember_01a01620-5909-77f5-a820-ef38d670480a" xlink:href="newt-20260930.xsd#newt_A2023StockIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_A2023And2015StockIncentivePlanMember_01a01620-5909-775d-bc27-506e8fb47481" xlink:to="loc_newt_A2023StockIncentivePlanMember_01a01620-5909-77f5-a820-ef38d670480a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2015EquityIncentivePlanMember_01a01620-5909-7c05-adee-df11caf6f169" xlink:href="newt-20260930.xsd#newt_A2015EquityIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_A2023And2015StockIncentivePlanMember_01a01620-5909-775d-bc27-506e8fb47481" xlink:to="loc_newt_A2015EquityIncentivePlanMember_01a01620-5909-7c05-adee-df11caf6f169" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a01620-5909-7a10-a1ee-dbbcbad5f65f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-74e3-808b-bdaa38fb8b90" xlink:to="loc_srt_RangeAxis_01a01620-5909-7a10-a1ee-dbbcbad5f65f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5909-7a10-a1ee-dbbcbad5f65f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_01a01620-5909-7a10-a1ee-dbbcbad5f65f" xlink:to="loc_srt_RangeMember_01a01620-5909-7a10-a1ee-dbbcbad5f65f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5909-7daf-b9db-57178ca186ae" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_01a01620-5909-7a10-a1ee-dbbcbad5f65f" xlink:to="loc_srt_RangeMember_01a01620-5909-7daf-b9db-57178ca186ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a01620-5909-7bf7-8ad0-8a7f543ea0f7" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5909-7daf-b9db-57178ca186ae" xlink:to="loc_srt_MinimumMember_01a01620-5909-7bf7-8ad0-8a7f543ea0f7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a01620-5909-7bdb-9f8c-02ab2703577a" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5909-7daf-b9db-57178ca186ae" xlink:to="loc_srt_MaximumMember_01a01620-5909-7bdb-9f8c-02ab2703577a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a01620-5909-76d5-855d-9974f5f8d4b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_01a01620-5909-76d5-855d-9974f5f8d4b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNetOfForfeituresInPeriod_01a01620-5909-77e2-a754-b6a9134e4d2e" xlink:href="newt-20260930.xsd#newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNetOfForfeituresInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsNetOfForfeituresInPeriod_01a01620-5909-77e2-a754-b6a9134e4d2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a01620-5909-712f-b729-0b8f0d2cc511" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a01620-5909-712f-b729-0b8f0d2cc511" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_01a01620-5909-710d-a670-61a5627de2b5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_01a01620-5909-710d-a670-61a5627de2b5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_01a01620-5909-7b64-8c6c-56d7aa24f6d1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7e45-b28c-55040787ba4d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_01a01620-5909-7b64-8c6c-56d7aa24f6d1" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSSharesOutstandingDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSSharesOutstandingDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSSharesOutstandingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7d89-af52-2c446a0c1bb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-770a-b112-104ca49e8b22" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7d89-af52-2c446a0c1bb1" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-770a-b112-104ca49e8b22" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a01620-5909-7cb0-9624-ed78b792a40a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-770a-b112-104ca49e8b22" xlink:to="loc_us-gaap_AwardTypeAxis_01a01620-5909-7cb0-9624-ed78b792a40a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cb0-9624-ed78b792a40a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7cb0-9624-ed78b792a40a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cb0-9624-ed78b792a40a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cd3-a720-1f6e36a5cd49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7cb0-9624-ed78b792a40a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cd3-a720-1f6e36a5cd49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01a01620-5909-75d4-b953-24e800e139c1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cd3-a720-1f6e36a5cd49" xlink:to="loc_us-gaap_RestrictedStockMember_01a01620-5909-75d4-b953-24e800e139c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_UnvestedRestrictedStockMember_01a01620-5909-7abd-a3b6-48866bf5aabb" xlink:href="newt-20260930.xsd#newt_UnvestedRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7cd3-a720-1f6e36a5cd49" xlink:to="loc_newt_UnvestedRestrictedStockMember_01a01620-5909-7abd-a3b6-48866bf5aabb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_01a01620-5909-7ad2-9925-54550ee4ebd9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7d89-af52-2c446a0c1bb1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_01a01620-5909-7ad2-9925-54550ee4ebd9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_01a01620-5909-7b6c-8296-51f30c0b3e02" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-7d89-af52-2c446a0c1bb1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_01a01620-5909-7b6c-8296-51f30c0b3e02" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSUnrecognizedCompensationDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSUnrecognizedCompensationDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSUnrecognizedCompensationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-71d0-b191-d0bcf2f34d2a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-77f5-b290-83a72a6d6276" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-71d0-b191-d0bcf2f34d2a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-77f5-b290-83a72a6d6276" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a01620-5909-7103-9860-2ae20ddbf03c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_01a01620-5909-77f5-b290-83a72a6d6276" xlink:to="loc_us-gaap_AwardTypeAxis_01a01620-5909-7103-9860-2ae20ddbf03c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7103-9860-2ae20ddbf03c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7103-9860-2ae20ddbf03c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7103-9860-2ae20ddbf03c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7855-9a6b-3172e70cc2b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7103-9860-2ae20ddbf03c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7855-9a6b-3172e70cc2b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01a01620-5909-7597-8df5-1a18bc296758" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7855-9a6b-3172e70cc2b7" xlink:to="loc_us-gaap_RestrictedStockMember_01a01620-5909-7597-8df5-1a18bc296758" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_01a01620-5909-7537-96c0-074104a515b7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-71d0-b191-d0bcf2f34d2a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_01a01620-5909-7537-96c0-074104a515b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01a01620-5909-7c03-91ad-e776b8ba9265" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01a01620-5909-71d0-b191-d0bcf2f34d2a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_01a01620-5909-7c03-91ad-e776b8ba9265" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSESPPInformationDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSESPPInformationDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSESPPInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-72a4-affb-ea2d71a0bbc1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7b84-89c7-0e5458acb84c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-72a4-affb-ea2d71a0bbc1" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7b84-89c7-0e5458acb84c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_01a01620-5909-78b8-b027-c7e613e15085" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7b84-89c7-0e5458acb84c" xlink:to="loc_us-gaap_PlanNameAxis_01a01620-5909-78b8-b027-c7e613e15085" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-78b8-b027-c7e613e15085_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-78b8-b027-c7e613e15085" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-78b8-b027-c7e613e15085_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-76cc-8d4b-cabd9372e2d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-78b8-b027-c7e613e15085" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-76cc-8d4b-cabd9372e2d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-745d-b901-6f3b430e6dea" xlink:href="newt-20260930.xsd#newt_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01a01620-5909-76cc-8d4b-cabd9372e2d5" xlink:to="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-745d-b901-6f3b430e6dea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_01a01620-5909-75c3-b630-e27e388810e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-72a4-affb-ea2d71a0bbc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_01a01620-5909-75c3-b630-e27e388810e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased_01a01620-5909-76b5-8747-7fbcd5580a15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-72a4-affb-ea2d71a0bbc1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerShareWeightedAveragePriceOfSharesPurchased_01a01620-5909-76b5-8747-7fbcd5580a15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardValuePurchasedForAward_01a01620-5909-7fa7-8525-e7c07419eafa" xlink:href="newt-20260930.xsd#newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardValuePurchasedForAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-72a4-affb-ea2d71a0bbc1" xlink:to="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardValuePurchasedForAward_01a01620-5909-7fa7-8525-e7c07419eafa" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSESPPActivityDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSESPPActivityDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSESPPActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-76ad-9924-a5659221d507" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-753c-9bd3-83663dce51b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-76ad-9924-a5659221d507" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-753c-9bd3-83663dce51b9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_01a01620-5909-79b1-84a6-253f6ebc3880" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-753c-9bd3-83663dce51b9" xlink:to="loc_us-gaap_PlanNameAxis_01a01620-5909-79b1-84a6-253f6ebc3880" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-79b1-84a6-253f6ebc3880_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-79b1-84a6-253f6ebc3880" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-79b1-84a6-253f6ebc3880_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-74b8-8ce4-73eae144ab86" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-79b1-84a6-253f6ebc3880" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-74b8-8ce4-73eae144ab86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-73ca-9e2c-f6ec546f0dd0" xlink:href="newt-20260930.xsd#newt_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01a01620-5909-74b8-8ce4-73eae144ab86" xlink:to="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-73ca-9e2c-f6ec546f0dd0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForFutureIssuanceRollForward_01a01620-5909-7d48-87ff-d411664aade1" xlink:href="newt-20260930.xsd#newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForFutureIssuanceRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-76ad-9924-a5659221d507" xlink:to="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForFutureIssuanceRollForward_01a01620-5909-7d48-87ff-d411664aade1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a01620-5909-78a9-9e21-38fe702739ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForFutureIssuanceRollForward_01a01620-5909-7d48-87ff-d411664aade1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a01620-5909-78a9-9e21-38fe702739ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_01a01620-5909-7af7-af6e-84db364d4adc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_newt_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesAvailableForFutureIssuanceRollForward_01a01620-5909-7d48-87ff-d411664aade1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesPurchasedForAward_01a01620-5909-7af7-af6e-84db364d4adc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_01a01620-5909-7945-b9de-f503d81497d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/BENEFITPLANSCompensationExpenseDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#BENEFITPLANSCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/BENEFITPLANSCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-73ea-8d83-61f4b3ec6c10" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7848-a56b-6992490c6ae4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-73ea-8d83-61f4b3ec6c10" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7848-a56b-6992490c6ae4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_01a01620-5909-7b49-abbd-5c145e41cb1e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7848-a56b-6992490c6ae4" xlink:to="loc_us-gaap_AwardTypeAxis_01a01620-5909-7b49-abbd-5c145e41cb1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7b49-abbd-5c145e41cb1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7b49-abbd-5c145e41cb1e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7b49-abbd-5c145e41cb1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7ed8-b9a3-6390fc95014b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_01a01620-5909-7b49-abbd-5c145e41cb1e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7ed8-b9a3-6390fc95014b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01a01620-5909-7104-90b9-e5a6b5ec42e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_01a01620-5909-7ed8-b9a3-6390fc95014b" xlink:to="loc_us-gaap_RestrictedStockMember_01a01620-5909-7104-90b9-e5a6b5ec42e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_01a01620-5909-7dd8-a8a2-155d7494558d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_01a01620-5909-7848-a56b-6992490c6ae4" xlink:to="loc_us-gaap_PlanNameAxis_01a01620-5909-7dd8-a8a2-155d7494558d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-7dd8-a8a2-155d7494558d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7dd8-a8a2-155d7494558d" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-7dd8-a8a2-155d7494558d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_01a01620-5909-738b-a2ac-a70f6867d3d9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_01a01620-5909-7dd8-a8a2-155d7494558d" xlink:to="loc_us-gaap_PlanNameDomain_01a01620-5909-738b-a2ac-a70f6867d3d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-7ead-9187-8e28436bb9c6" xlink:href="newt-20260930.xsd#newt_EmployeeStockPurchasePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_01a01620-5909-738b-a2ac-a70f6867d3d9" xlink:to="loc_newt_EmployeeStockPurchasePlanMember_01a01620-5909-7ead-9187-8e28436bb9c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a01620-5909-7b20-9d35-8ebe810b0bea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_01a01620-5909-73ea-8d83-61f4b3ec6c10" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_01a01620-5909-7b20-9d35-8ebe810b0bea" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SEGMENTSDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SEGMENTSDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SEGMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a01620-5909-7636-ba24-957da64b1b4e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a01620-5909-7636-ba24-957da64b1b4e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_01a01620-5909-7d07-b3cf-212863ee13e9" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a01620-5909-7636-ba24-957da64b1b4e" xlink:to="loc_srt_ConsolidationItemsAxis_01a01620-5909-7d07-b3cf-212863ee13e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a01620-5909-7d07-b3cf-212863ee13e9_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_01a01620-5909-7d07-b3cf-212863ee13e9" xlink:to="loc_srt_ConsolidationItemsDomain_01a01620-5909-7d07-b3cf-212863ee13e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_01a01620-5909-7fad-8063-97d22c1590ee" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_01a01620-5909-7d07-b3cf-212863ee13e9" xlink:to="loc_srt_ConsolidationItemsDomain_01a01620-5909-7fad-8063-97d22c1590ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_01a01620-5909-70ae-86fb-86cb1ef7b959" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_01a01620-5909-7fad-8063-97d22c1590ee" xlink:to="loc_us-gaap_OperatingSegmentsMember_01a01620-5909-70ae-86fb-86cb1ef7b959" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_01a01620-5909-79fc-a400-41bde2074c4d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_01a01620-5909-7fad-8063-97d22c1590ee" xlink:to="loc_us-gaap_IntersegmentEliminationMember_01a01620-5909-79fc-a400-41bde2074c4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_01a01620-5909-7319-b7bf-1904e31d3171" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_01a01620-5909-7fad-8063-97d22c1590ee" xlink:to="loc_us-gaap_CorporateNonSegmentMember_01a01620-5909-7319-b7bf-1904e31d3171" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5909-7e12-b86e-61f6525eb4a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a01620-5909-7636-ba24-957da64b1b4e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5909-7e12-b86e-61f6525eb4a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5909-7e12-b86e-61f6525eb4a6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5909-7e12-b86e-61f6525eb4a6" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5909-7e12-b86e-61f6525eb4a6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_01a01620-5909-7e12-b86e-61f6525eb4a6" xlink:to="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_BankingSegmentMember_01a01620-5909-7f62-9435-2b5bfb8537a6" xlink:href="newt-20260930.xsd#newt_BankingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:to="loc_newt_BankingSegmentMember_01a01620-5909-7f62-9435-2b5bfb8537a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_AlternativeLendingMember_01a01620-5909-775b-9470-7ed71a1b1bd2" xlink:href="newt-20260930.xsd#newt_AlternativeLendingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:to="loc_newt_AlternativeLendingMember_01a01620-5909-775b-9470-7ed71a1b1bd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_NSBFMember_01a01620-5909-7ee5-ac51-a6646a4138e6" xlink:href="newt-20260930.xsd#newt_NSBFMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:to="loc_newt_NSBFMember_01a01620-5909-7ee5-ac51-a6646a4138e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_PaymentsMember_01a01620-5909-7c35-a313-20445f07774e" xlink:href="newt-20260930.xsd#newt_PaymentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_01a01620-5909-7f8e-8190-a09080fc4a8e" xlink:to="loc_newt_PaymentsMember_01a01620-5909-7c35-a313-20445f07774e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_01a01620-5909-7035-9e40-e2f24c42304f" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_01a01620-5909-7636-ba24-957da64b1b4e" xlink:to="loc_srt_RangeAxis_01a01620-5909-7035-9e40-e2f24c42304f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5909-7035-9e40-e2f24c42304f_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_01a01620-5909-7035-9e40-e2f24c42304f" xlink:to="loc_srt_RangeMember_01a01620-5909-7035-9e40-e2f24c42304f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_01a01620-5909-7c9a-b6aa-fe5fd59f5976" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_01a01620-5909-7035-9e40-e2f24c42304f" xlink:to="loc_srt_RangeMember_01a01620-5909-7c9a-b6aa-fe5fd59f5976" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_01a01620-5909-7714-9349-d8eb052e039e" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5909-7c9a-b6aa-fe5fd59f5976" xlink:to="loc_srt_MinimumMember_01a01620-5909-7714-9349-d8eb052e039e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_01a01620-5909-76db-be7a-e51266c43359" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_01a01620-5909-7c9a-b6aa-fe5fd59f5976" xlink:to="loc_srt_MaximumMember_01a01620-5909-76db-be7a-e51266c43359" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SegmentAllocationGoodwillPercentage_01a01620-5909-7e7e-b666-85289f4af832" xlink:href="newt-20260930.xsd#newt_SegmentAllocationGoodwillPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_newt_SegmentAllocationGoodwillPercentage_01a01620-5909-7e7e-b666-85289f4af832" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_SegmentAllocationEquityCapitalPercentage_01a01620-5909-7e33-83ed-1ad5f98b9f02" xlink:href="newt-20260930.xsd#newt_SegmentAllocationEquityCapitalPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_newt_SegmentAllocationEquityCapitalPercentage_01a01620-5909-7e33-83ed-1ad5f98b9f02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_01a01620-5909-797d-a939-382e4c1a0ae8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_NumberOfReportableSegments_01a01620-5909-797d-a939-382e4c1a0ae8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_01a01620-5909-7c0d-89da-a53f74654198" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_NumberOfOperatingSegments_01a01620-5909-7c0d-89da-a53f74654198" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperating_01a01620-5909-7fd0-86bd-8347c39ad9a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_InterestIncomeOperating_01a01620-5909-7fd0-86bd-8347c39ad9a2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_01a01620-5909-7993-9657-6a325e38c1fb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_InterestExpenseOperating_01a01620-5909-7993-9657-6a325e38c1fb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_01a01620-5909-7cc5-a9a7-2f5a315a9123" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_01a01620-5909-7cc5-a9a7-2f5a315a9123" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-5909-7f90-980e-b02c7e4ca3b2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_01a01620-5909-7f90-980e-b02c7e4ca3b2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_01a01620-5909-70d1-b94a-67aabf3f4029" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_InterestIncomeExpenseAfterProvisionForLoanLoss_01a01620-5909-70d1-b94a-67aabf3f4029" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoninterestIncome_01a01620-5909-7bdd-b4d7-8e768535cfc4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NoninterestIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_NoninterestIncome_01a01620-5909-7bdd-b4d7-8e768535cfc4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_01a01620-5909-7403-b2a4-e55300a22174" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_LaborAndRelatedExpense_01a01620-5909-7403-b2a4-e55300a22174" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_ElectronicPaymentProcessingExpense_01a01620-5909-7408-99e0-fa539e633d48" xlink:href="newt-20260930.xsd#newt_ElectronicPaymentProcessingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_newt_ElectronicPaymentProcessingExpense_01a01620-5909-7408-99e0-fa539e633d48" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfessionalFees_01a01620-5909-7bfe-9aea-b8d90c8a8a5a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProfessionalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_ProfessionalFees_01a01620-5909-7bfe-9aea-b8d90c8a8a5a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_LoanProcessingFeeOther_01a01620-5909-76e8-9bcc-3561a8fb8384" xlink:href="newt-20260930.xsd#newt_LoanProcessingFeeOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_newt_LoanProcessingFeeOther_01a01620-5909-76e8-9bcc-3561a8fb8384" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_01a0b097-7068-7006-aadd-826328ff5269" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_01a0b097-7068-7006-aadd-826328ff5269" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InformationTechnologyAndDataProcessing_01a01620-5909-7644-bd6c-ed7841a19127" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InformationTechnologyAndDataProcessing"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_InformationTechnologyAndDataProcessing_01a01620-5909-7644-bd6c-ed7841a19127" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a01620-5909-7bdb-9d4d-29f131bb056b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_OtherGeneralAndAdministrativeExpense_01a01620-5909-7bdb-9d4d-29f131bb056b" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossAttributableToParent_01a01620-5909-7df0-87ec-571d627c5839" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_IncomeLossAttributableToParent_01a01620-5909-7df0-87ec-571d627c5839" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_01a01620-5909-7402-8d51-45557c9ad9fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_01a01620-5909-7402-8d51-45557c9ad9fd" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_01a01620-5909-7e68-9171-90f8dc329bcf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_NetIncomeLoss_01a01620-5909-7e68-9171-90f8dc329bcf" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_01a01620-5909-787c-a72f-d7f63b8d0e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_Assets_01a01620-5909-787c-a72f-d7f63b8d0e3a" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_01a01620-5909-71d8-b0eb-23889b9bce06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_01a01620-5909-71d8-b0eb-23889b9bce06" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_01a01620-5909-757e-a033-c4b666431f2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_01a01620-5909-76d4-8df5-71923fd7b08b" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_01a01620-5909-757e-a033-c4b666431f2f" xlink:type="arc" order="22"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.newtekone.com/role/SUBSEQUENTEVENTSDetails" xlink:type="simple" xlink:href="newt-20260930.xsd#SUBSEQUENTEVENTSDetails"/>
  <link:definitionLink xlink:role="http://www.newtekone.com/role/SUBSEQUENTEVENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_01a01620-5909-755a-9e15-6e579213e315" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_01a01620-5909-755a-9e15-6e579213e315" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a01620-5909-755a-9e15-6e579213e315_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a01620-5909-755a-9e15-6e579213e315" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a01620-5909-755a-9e15-6e579213e315_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_01a01620-5909-7145-8a46-c4adf2cb89ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_01a01620-5909-755a-9e15-6e579213e315" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_01a01620-5909-7145-8a46-c4adf2cb89ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_01a01620-5909-7e5d-99a7-34e52f2c84e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_01a01620-5909-7145-8a46-c4adf2cb89ab" xlink:to="loc_us-gaap_SubsequentEventMember_01a01620-5909-7e5d-99a7-34e52f2c84e8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_01a11758-d844-71e2-82c2-ef9a8040a810" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:to="loc_srt_ShareRepurchaseProgramAxis_01a11758-d844-71e2-82c2-ef9a8040a810" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a11758-d844-71e2-82c2-ef9a8040a810_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a11758-d844-71e2-82c2-ef9a8040a810" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a11758-d844-71e2-82c2-ef9a8040a810_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_01a11758-d844-7c82-839a-ecbd7718ac5c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_01a11758-d844-71e2-82c2-ef9a8040a810" xlink:to="loc_srt_ShareRepurchaseProgramDomain_01a11758-d844-7c82-839a-ecbd7718ac5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_TransactionAgreementMember_01a11759-0e00-7a7f-accd-7c846a25cc3c" xlink:href="newt-20260930.xsd#newt_TransactionAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_01a11758-d844-7c82-839a-ecbd7718ac5c" xlink:to="loc_newt_TransactionAgreementMember_01a11759-0e00-7a7f-accd-7c846a25cc3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_01a1835b-a30f-7ae6-9bdf-e5268b0cb860" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:to="loc_us-gaap_DebtInstrumentAxis_01a1835b-a30f-7ae6-9bdf-e5268b0cb860" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-7ae6-9bdf-e5268b0cb860_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a1835b-a30f-7ae6-9bdf-e5268b0cb860" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-7ae6-9bdf-e5268b0cb860_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-79b2-9648-0fae48e27b8f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_01a1835b-a30f-7ae6-9bdf-e5268b0cb860" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-79b2-9648-0fae48e27b8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A2027NotesMember_01a18360-cdca-7041-ac95-581a57c5628a" xlink:href="newt-20260930.xsd#newt_A2027NotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-79b2-9648-0fae48e27b8f" xlink:to="loc_newt_A2027NotesMember_01a18360-cdca-7041-ac95-581a57c5628a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_A8.125FixedRateSeniorNotesDueFebruary12029Member_01a18363-bc19-7c5e-b70a-86c24eff5e10" xlink:href="newt-20260930.xsd#newt_A8.125FixedRateSeniorNotesDueFebruary12029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_01a1835b-a30f-79b2-9648-0fae48e27b8f" xlink:to="loc_newt_A8.125FixedRateSeniorNotesDueFebruary12029Member_01a18363-bc19-7c5e-b70a-86c24eff5e10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_01a18363-3256-7df5-b0e5-e834bfd931bb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_01a01620-5909-705e-9ce8-b80df5bc0678" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_01a18363-3256-7df5-b0e5-e834bfd931bb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a18363-3256-7df5-b0e5-e834bfd931bb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a18363-3256-7df5-b0e5-e834bfd931bb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a18363-3256-7df5-b0e5-e834bfd931bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_01a18363-3256-7468-9604-d5d74d10b0a2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_01a18363-3256-7df5-b0e5-e834bfd931bb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_01a18363-3256-7468-9604-d5d74d10b0a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_01a18363-4c1f-78ee-bef6-7904f0e86b39" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_01a18363-3256-7468-9604-d5d74d10b0a2" xlink:to="loc_us-gaap_SeniorNotesMember_01a18363-4c1f-78ee-bef6-7904f0e86b39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a11758-9ad1-7e4b-a780-e5fc6c44c2bd" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_01a11758-9ad1-7e4b-a780-e5fc6c44c2bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAmount_01a1835b-a30f-7912-be95-adf8951326b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ExtinguishmentOfDebtAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAmount_01a1835b-a30f-7912-be95-adf8951326b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a18361-d7ac-7b31-a41d-1bb4ae18762c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_01a18361-d7ac-7b31-a41d-1bb4ae18762c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_01a18364-e4e7-7cb8-b372-fcd0ce8cfe07" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_01a18364-e4e7-7cb8-b372-fcd0ce8cfe07" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a1836b-1039-7d12-bf87-2d07a55b0e37" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_01a1836b-1039-7d12-bf87-2d07a55b0e37" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentRedemptionMinimumTimeToRedeem_01a18373-79a9-7cd6-9d58-8afaf9b119b0" xlink:href="newt-20260930.xsd#newt_DebtInstrumentRedemptionMinimumTimeToRedeem"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_newt_DebtInstrumentRedemptionMinimumTimeToRedeem_01a18373-79a9-7cd6-9d58-8afaf9b119b0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_newt_DebtInstrumentRedemptionMaximumTimeToRedeem_01a18374-bd45-7b59-a598-3a89c64c0607" xlink:href="newt-20260930.xsd#newt_DebtInstrumentRedemptionMaximumTimeToRedeem"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_01a01620-5909-7baf-93a7-eb4c65d3c343" xlink:to="loc_newt_DebtInstrumentRedemptionMaximumTimeToRedeem_01a18374-bd45-7b59-a598-3a89c64c0607" xlink:type="arc" order="6"/>
  </link:definitionLink>
</link:linkbase>
