﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xsi:schemaLocation="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2024v5.2">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2025-09-25T11:44:34-05:00</ReturnTs>
    <TaxPeriodEndDt>2024-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmName>
        <BusinessNameLine1Txt>Foundation Source</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>3333 New Hyde Park Rd Ste 406</AddressLine1Txt>
        <CityNm>New Hyde Park</CityNm>
        <StateAbbreviationCd>NY</StateAbbreviationCd>
        <ZIPCd>11042</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990PF</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-09-11</TaxPeriodBeginDt>
    <Filer>
      <EIN>331582054</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>STK Foundation</BusinessNameLine1Txt>
      </BusinessName>
      <InCareOfNm>% FOUNDATION SOURCE</InCareOfNm>
      <BusinessNameControlTxt>KOUS</BusinessNameControlTxt>
      <PhoneNum>8008391754</PhoneNum>
      <USAddress>
        <AddressLine1Txt>FOUNDATION SOURCE 501 SILVERSIDE RD</AddressLine1Txt>
        <CityNm>WILMINGTON</CityNm>
        <StateAbbreviationCd>DE</StateAbbreviationCd>
        <ZIPCd>198091377</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>Takashi Kousaka</PersonNm>
      <PersonTitleTxt>President</PersonTitleTxt>
      <PhoneNum>8008391754</PhoneNum>
      <SignatureDt>2025-08-08</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>true</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>Jeffrey D Haskell</PreparerPersonNm>
      <PTIN>P01345770</PTIN>
      <PhoneNum>8008391754</PhoneNum>
    </PreparerPersonGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="4">
    <IRS990PF documentId="IRS990PF">
      <InitialReturnInd>X</InitialReturnInd>
      <NameChangeInd>X</NameChangeInd>
      <Organization501c3ExemptPFInd>X</Organization501c3ExemptPFInd>
      <FMVAssetsEOYAmt>5020825</FMVAssetsEOYAmt>
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <AnalysisOfRevenueAndExpenses>
        <ContriRcvdRevAndExpnssAmt>5020000</ContriRcvdRevAndExpnssAmt>
        <InterestOnSavRevAndExpnssAmt>825</InterestOnSavRevAndExpnssAmt>
        <InterestOnSavNetInvstIncmAmt>825</InterestOnSavNetInvstIncmAmt>
        <CapGainNetIncmNetInvstIncmAmt>0</CapGainNetIncmNetInvstIncmAmt>
        <TotalRevAndExpnssAmt>5020825</TotalRevAndExpnssAmt>
        <TotalNetInvstIncmAmt>825</TotalNetInvstIncmAmt>
        <CompOfcrDirTrstRevAndExpnssAmt>0</CompOfcrDirTrstRevAndExpnssAmt>
        <TotOprExpensesRevAndExpnssAmt>0</TotOprExpensesRevAndExpnssAmt>
        <TotOprExpensesNetInvstIncmAmt>0</TotOprExpensesNetInvstIncmAmt>
        <TotOprExpensesDsbrsChrtblAmt>0</TotOprExpensesDsbrsChrtblAmt>
        <ContriPaidRevAndExpnssAmt>0</ContriPaidRevAndExpnssAmt>
        <ContriPaidDsbrsChrtblAmt>0</ContriPaidDsbrsChrtblAmt>
        <TotalExpensesRevAndExpnssAmt>0</TotalExpensesRevAndExpnssAmt>
        <TotalExpensesNetInvstIncmAmt>0</TotalExpensesNetInvstIncmAmt>
        <TotalExpensesDsbrsChrtblAmt>0</TotalExpensesDsbrsChrtblAmt>
        <ExcessRevenueOverExpensesAmt>5020825</ExcessRevenueOverExpensesAmt>
        <NetInvestmentIncomeAmt>825</NetInvestmentIncomeAmt>
        <AdjustedNetIncomeAmt>0</AdjustedNetIncomeAmt>
      </AnalysisOfRevenueAndExpenses>
      <Form990PFBalanceSheetsGrp>
        <SavAndTempCashInvstEOYAmt>5020825</SavAndTempCashInvstEOYAmt>
        <SavAndTempCashInvstEOYFMVAmt>5020825</SavAndTempCashInvstEOYFMVAmt>
        <TotalAssetsBOYAmt>0</TotalAssetsBOYAmt>
        <TotalAssetsEOYAmt>5020825</TotalAssetsEOYAmt>
        <TotalAssetsEOYFMVAmt>5020825</TotalAssetsEOYFMVAmt>
        <TotalLiabilitiesBOYAmt>0</TotalLiabilitiesBOYAmt>
        <TotalLiabilitiesEOYAmt>0</TotalLiabilitiesEOYAmt>
        <OrgDoesNotFollowFASB117Ind>X</OrgDoesNotFollowFASB117Ind>
        <RetainedEarningEOYAmt>5020825</RetainedEarningEOYAmt>
        <TotNetAstOrFundBalancesBOYAmt>0</TotNetAstOrFundBalancesBOYAmt>
        <TotNetAstOrFundBalancesEOYAmt>5020825</TotNetAstOrFundBalancesEOYAmt>
        <TotalLiabilitiesNetAstBOYAmt>0</TotalLiabilitiesNetAstBOYAmt>
        <TotalLiabilitiesNetAstEOYAmt>5020825</TotalLiabilitiesNetAstEOYAmt>
      </Form990PFBalanceSheetsGrp>
      <ChgInNetAssetsFundBalancesGrp>
        <TotNetAstOrFundBalancesBOYAmt>0</TotNetAstOrFundBalancesBOYAmt>
        <ExcessRevenueOverExpensesAmt>5020825</ExcessRevenueOverExpensesAmt>
        <SubtotalAmt>5020825</SubtotalAmt>
        <TotNetAstOrFundBalancesEOYAmt>5020825</TotNetAstOrFundBalancesEOYAmt>
      </ChgInNetAssetsFundBalancesGrp>
      <CapGainsLossTxInvstIncmDetail />
      <ExciseTaxBasedOnInvstIncmGrp>
        <InvestmentIncomeExciseTaxAmt>11</InvestmentIncomeExciseTaxAmt>
        <SubtotalAmt>11</SubtotalAmt>
        <TaxBasedOnInvestmentIncomeAmt>11</TaxBasedOnInvestmentIncomeAmt>
        <ExemptFrgnOrgTaxWthldAtSrceAmt>0</ExemptFrgnOrgTaxWthldAtSrceAmt>
        <ExtsnRequestIncomeTaxPaidAmt>100</ExtsnRequestIncomeTaxPaidAmt>
        <TotalPaymentsAndCreditsAmt>100</TotalPaymentsAndCreditsAmt>
        <OverpaymentAmt>89</OverpaymentAmt>
        <AppliedToESTaxAmt>89</AppliedToESTaxAmt>
      </ExciseTaxBasedOnInvstIncmGrp>
      <StatementsRegardingActyGrp>
        <LegislativePoliticalActyInd referenceDocumentId="BinaryAttach">false</LegislativePoliticalActyInd>
        <MoreThan100SpentInd>false</MoreThan100SpentInd>
        <Form1120POLFiledInd>false</Form1120POLFiledInd>
        <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
        <ChangesToArticlesOrBylawsInd referenceDocumentId="BinaryAttach">false</ChangesToArticlesOrBylawsInd>
        <UnrelatedBusIncmOverLimitInd>false</UnrelatedBusIncmOverLimitInd>
        <OrganizationDissolvedEtcInd referenceDocumentId="BinaryAttach">false</OrganizationDissolvedEtcInd>
        <Section508eRqrSatisfiedInd>true</Section508eRqrSatisfiedInd>
        <AtLeast5000InAssetsInd>true</AtLeast5000InAssetsInd>
        <OrgReportOrRegisterStateCd>DE</OrgReportOrRegisterStateCd>
        <Form990PFFiledWithAttyGenInd>true</Form990PFFiledWithAttyGenInd>
        <PrivateOperatingFoundationInd>false</PrivateOperatingFoundationInd>
        <NewSubstantialContributorsInd referenceDocumentId="SubsContributorsSch">true</NewSubstantialContributorsInd>
        <OwnControlledEntityInd>false</OwnControlledEntityInd>
        <DonorAdvisedFundInd>false</DonorAdvisedFundInd>
        <ComplyWithPublicInspRqrInd>true</ComplyWithPublicInspRqrInd>
        <PersonsWithBooksName>
          <BusinessNameLine1Txt>FOUNDATION SOURCE</BusinessNameLine1Txt>
        </PersonsWithBooksName>
        <PhoneNum>8008391754</PhoneNum>
        <LocationOfBooksUSAddress>
          <AddressLine1Txt>501 SILVERSIDE ROAD SUITE 123</AddressLine1Txt>
          <CityNm>WILMINGTON</CityNm>
          <StateAbbreviationCd>DE</StateAbbreviationCd>
          <ZIPCd>198091377</ZIPCd>
        </LocationOfBooksUSAddress>
        <ForeignAccountsQuestionInd>false</ForeignAccountsQuestionInd>
      </StatementsRegardingActyGrp>
      <StatementsRegardingActy4720Grp>
        <SaleOrExchDisqualifiedPrsnInd>false</SaleOrExchDisqualifiedPrsnInd>
        <BrrwOrLendDisqualifiedPrsnInd>false</BrrwOrLendDisqualifiedPrsnInd>
        <FurnGoodsDisqualifiedPrsnInd>false</FurnGoodsDisqualifiedPrsnInd>
        <PayCompDisqualifiedPrsnInd>false</PayCompDisqualifiedPrsnInd>
        <TransferAstDisqualifiedPrsnInd>false</TransferAstDisqualifiedPrsnInd>
        <PaymentToGovernmentOfficialInd>false</PaymentToGovernmentOfficialInd>
        <UncorrectedPriorActsInd>false</UncorrectedPriorActsInd>
        <UndistributedIncomePYInd>false</UndistributedIncomePYInd>
        <BusinessHoldingsInd>false</BusinessHoldingsInd>
        <JeopardyInvestmentsInd>false</JeopardyInvestmentsInd>
        <UncorrectedPYJeopardyInvstInd>false</UncorrectedPYJeopardyInvstInd>
        <InfluenceLegislationInd>false</InfluenceLegislationInd>
        <InfluenceElectionInd>false</InfluenceElectionInd>
        <GrantsToIndividualsInd>false</GrantsToIndividualsInd>
        <GrantsToOrganizationsInd>false</GrantsToOrganizationsInd>
        <NoncharitablePurposeInd>false</NoncharitablePurposeInd>
        <RcvFndsToPayPrsnlBnftCntrctInd>false</RcvFndsToPayPrsnlBnftCntrctInd>
        <PayPremiumsPrsnlBnftCntrctInd>false</PayPremiumsPrsnlBnftCntrctInd>
        <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
        <SubjToTaxRmnrtnExPrchtPymtInd>false</SubjToTaxRmnrtnExPrchtPymtInd>
      </StatementsRegardingActy4720Grp>
      <OfficerDirTrstKeyEmplInfoGrp>
        <OfficerDirTrstKeyEmplGrp>
          <PersonNm>Takashi Kousaka</PersonNm>
          <USAddress>
            <AddressLine1Txt>FOUNDATION SOURCE 501 SILVERSIDE RD</AddressLine1Txt>
            <CityNm>WILMINGTON</CityNm>
            <StateAbbreviationCd>DE</StateAbbreviationCd>
            <ZIPCd>198091377</ZIPCd>
          </USAddress>
          <TitleTxt>pres, Dir, Sec, Treas</TitleTxt>
          <AverageHrsPerWkDevotedToPosRt>1.0</AverageHrsPerWkDevotedToPosRt>
          <CompensationAmt>0</CompensationAmt>
          <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
          <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
        </OfficerDirTrstKeyEmplGrp>
      </OfficerDirTrstKeyEmplInfoGrp>
      <SummaryOfDirectChrtblActyGrp />
      <SumOfProgramRelatedInvstGrp />
      <MinimumInvestmentReturnGrp>
        <AverageMonthlyFMVOfSecAmt>0</AverageMonthlyFMVOfSecAmt>
        <AverageMonthlyCashBalancesAmt>632603</AverageMonthlyCashBalancesAmt>
        <FMVAllOtherNoncharitableAstAmt>0</FMVAllOtherNoncharitableAstAmt>
        <TotalFMVOfUnusedAssetsAmt>632603</TotalFMVOfUnusedAssetsAmt>
        <AcquisitionIndebtednessAmt>0</AcquisitionIndebtednessAmt>
        <AdjustedTotalFMVOfUnusedAstAmt>632603</AdjustedTotalFMVOfUnusedAstAmt>
        <CashDeemedCharitableAmt>9489</CashDeemedCharitableAmt>
        <NetVlNoncharitableAssetsAmt>623114</NetVlNoncharitableAssetsAmt>
        <MinimumInvestmentReturnAmt>9534</MinimumInvestmentReturnAmt>
      </MinimumInvestmentReturnGrp>
      <DistributableAmountGrp>
        <MinimumInvestmentReturnAmt>9534</MinimumInvestmentReturnAmt>
        <TaxBasedOnInvestmentIncomeAmt>11</TaxBasedOnInvestmentIncomeAmt>
        <TotalTaxAmt>11</TotalTaxAmt>
        <DistributableBeforeAdjAmt>9523</DistributableBeforeAdjAmt>
        <DistributableBeforeDedAmt>9523</DistributableBeforeDedAmt>
        <DistributableAsAdjustedAmt>9523</DistributableAsAdjustedAmt>
      </DistributableAmountGrp>
      <PFQualifyingDistributionsGrp>
        <ExpensesAndContributionsAmt>0</ExpensesAndContributionsAmt>
        <ProgramRelatedInvstTotalAmt>0</ProgramRelatedInvstTotalAmt>
        <CharitableAssetsAcquisPaidAmt>0</CharitableAssetsAcquisPaidAmt>
        <SetAsideSuitabilityTestAmt>0</SetAsideSuitabilityTestAmt>
        <SetAsideCashDistriTestAmt>0</SetAsideCashDistriTestAmt>
        <QualifyingDistributionsAmt>0</QualifyingDistributionsAmt>
      </PFQualifyingDistributionsGrp>
      <UndistributedIncomeGrp>
        <DistributableAsAdjustedAmt>9523</DistributableAsAdjustedAmt>
        <QualifyingDistributionsAmt>0</QualifyingDistributionsAmt>
        <RemainingDistriFromCorpusAmt>0</RemainingDistriFromCorpusAmt>
        <TotalCorpusAmt>0</TotalCorpusAmt>
        <UndistributedIncomeCYAmt>9523</UndistributedIncomeCYAmt>
        <ExcessDistriCyovToNextYrAmt>0</ExcessDistriCyovToNextYrAmt>
        <ExcessFromCurrentYearAmt>0</ExcessFromCurrentYearAmt>
      </UndistributedIncomeGrp>
      <PrivateOperatingFoundationsGrp></PrivateOperatingFoundationsGrp>
      <SupplementaryInformationGrp>
        <ContributingManagerNm>TAKASHI KOUSAKA</ContributingManagerNm>
        <OnlyContriToPreselectedInd>X</OnlyContriToPreselectedInd>
      </SupplementaryInformationGrp>
      <AnalysisIncomeProducingActyGrp>
        <FeesContractsFromGovtAgGrp />
        <MembershipDuesAndAssmntGrp />
        <IntOnSavAndTempCashInvstGrp>
          <ExclusionCd>14</ExclusionCd>
          <ExclusionAmt>825</ExclusionAmt>
        </IntOnSavAndTempCashInvstGrp>
        <DividendsAndInterestFromSecDtl />
        <NetRntlIncmReDebtFincdPropGrp />
        <NetRntlIncmReNotDebtFincdProp />
        <NetRentalIncomePersonalPropGrp />
        <OtherInvestmentIncomeGrp />
        <GainSalesAstOthThanInvntryGrp />
        <NetIncomeLossFromSpecialEvtGrp />
        <GrossProfitLossSlsOfInvntryGrp />
        <SubtotalsIncmProducingActyGrp>
          <ExclusionAmt>825</ExclusionAmt>
        </SubtotalsIncmProducingActyGrp>
        <TotalIncomeProducingActyAmt>825</TotalIncomeProducingActyAmt>
      </AnalysisIncomeProducingActyGrp>
      <TrnsfrTransRlnNonchrtblEOGrp>
        <TrnsfrOfCashToNonchrtblEOInd>false</TrnsfrOfCashToNonchrtblEOInd>
        <TrnsfrOtherAssetNonchrtblEOInd>false</TrnsfrOtherAssetNonchrtblEOInd>
        <SalesOrExchangesOfAssetsInd>false</SalesOrExchangesOfAssetsInd>
        <PurchaseOfAssetsNonchrtblEOInd>false</PurchaseOfAssetsNonchrtblEOInd>
        <RentalOfFacilitiesOthAssetsInd>false</RentalOfFacilitiesOthAssetsInd>
        <ReimbursementArrangementsInd>false</ReimbursementArrangementsInd>
        <LoansOrLoanGuaranteesInd>false</LoansOrLoanGuaranteesInd>
        <PerformanceOfServicesEtcInd>false</PerformanceOfServicesEtcInd>
        <SharingOfFacilitiesEtcInd>false</SharingOfFacilitiesEtcInd>
        <RelationshipsNonchrtblEOInd>false</RelationshipsNonchrtblEOInd>
      </TrnsfrTransRlnNonchrtblEOGrp>
    </IRS990PF>
    <IRS990ScheduleB documentId="IRS990ScheduleB">
      <Organization501c3ExemptPFInd>X</Organization501c3ExemptPFInd>
      <GeneralRuleInd>X</GeneralRuleInd>
      <ContributorInformationGrp>
        <ContributorNum>1</ContributorNum>
        <ContributorPersonNm>Kousaka Takashi</ContributorPersonNm>
        <ContributorUSAddress>
          <AddressLine1Txt>Foundation Source 55 Walls Dr Fl 3</AddressLine1Txt>
          <CityNm>Fairfield</CityNm>
          <StateAbbreviationCd>CT</StateAbbreviationCd>
          <ZIPCd>06824</ZIPCd>
        </ContributorUSAddress>
        <TotalContributionsAmt>5020000</TotalContributionsAmt>
        <PersonContributionInd>X</PersonContributionInd>
      </ContributorInformationGrp>
    </IRS990ScheduleB>
    <DepreciationSchedule documentId="DepreciationSch" />
    <SubstantialContributorsSch documentId="SubsContributorsSch">
      <SubstantialContributorDetail>
        <PersonNm>Kousaka Takashi</PersonNm>
        <USAddress>
          <AddressLine1Txt>Foundation Source 55 Walls Dr Fl 3</AddressLine1Txt>
          <CityNm>Fairfield</CityNm>
          <StateAbbreviationCd>CT</StateAbbreviationCd>
          <ZIPCd>06824</ZIPCd>
        </USAddress>
      </SubstantialContributorDetail>
    </SubstantialContributorsSch>
  </ReturnData>
</Return>