<?xml version="1.0" encoding="US-ASCII" standalone="no"?>
    <!-- Field: Doc-Info; Name: Generator; Value: GoFiler Complete; Version: 6.5b -->
    <!-- Field: Doc-Info; Name: VendorURI; Value: https://www.novaworks.com -->
    <!-- Field: Doc-Info; Name: Status; Value: 0x00000000 -->
<link:linkbase xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByIndustrySector" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByIndustrySector" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByGeographicRegion" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByGeographicRegion" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByCreditQuality" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByCreditQuality" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByMaturity" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByMaturity" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByAssetCategory" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByAssetCategory" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByOtherCategory" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByOtherCategory" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingsByOtherCategory2" roleURI="http://xbrl.sec.gov/oef/role/HoldingsByOtherCategory2" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#LargestHoldings" roleURI="http://xbrl.sec.gov/oef/role/LargestHoldings" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#ProspectusOnly" roleURI="http://xbrl.sec.gov/rr/role/ProspectusOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#RiskOnly" roleURI="http://xbrl.sec.gov/rr/role/RiskOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#CoregistrantOnly" roleURI="http://xbrl.sec.gov/oef/role/CoregistrantOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#SeriesOnly" roleURI="http://xbrl.sec.gov/oef/role/SeriesOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#ClassOnly" roleURI="http://xbrl.sec.gov/oef/role/ClassOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#PerformanceMeasureOnly" roleURI="http://xbrl.sec.gov/rr/role/PerformanceMeasureOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingAssetCategoryOnly" roleURI="http://xbrl.sec.gov/oef/role/HoldingAssetCategoryOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#BroadBasedIndexOnly" roleURI="http://xbrl.sec.gov/oef/role/BroadBasedIndexOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#AdditionalIndexOnly" roleURI="http://xbrl.sec.gov/oef/role/AdditionalIndexOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#IndustrySectorOnly" roleURI="http://xbrl.sec.gov/oef/role/IndustrySectorOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#GeographicRegionOnly" roleURI="http://xbrl.sec.gov/oef/role/GeographicRegionOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#CreditQualityOnly" roleURI="http://xbrl.sec.gov/oef/role/CreditQualityOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#MaturityOnly" roleURI="http://xbrl.sec.gov/oef/role/MaturityOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#Other1CategoryOnly" roleURI="http://xbrl.sec.gov/oef/role/Other1CategoryOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#Other2CategoryOnly" roleURI="http://xbrl.sec.gov/oef/role/Other2CategoryOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#LargestHoldingOnly" roleURI="http://xbrl.sec.gov/oef/role/LargestHoldingOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#SalesLoadOnly" roleURI="http://xbrl.sec.gov/oef/role/SalesLoadOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#HoldingMeasureOnly" roleURI="http://xbrl.sec.gov/oef/role/HoldingMeasureOnly" />
    <link:roleRef xlink:type="simple" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#ValueMeasureOnly" roleURI="http://xbrl.sec.gov/oef/role/ValueMeasureOnly" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" arcroleURI="http://xbrl.org/int/dim/arcrole/all" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#notAll" arcroleURI="http://xbrl.org/int/dim/arcrole/notAll" />
    <link:arcroleRef xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/rr/role/ProspectusOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/rr/role/RiskOnly">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_AllRisksMember" xlink:label="loc_oefAllRisksMember" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_YieldCurveRiskMember" xlink:label="loc_horzYieldCurveRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzYieldCurveRiskMember" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ManagementRiskMember" xlink:label="loc_horzManagementRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzManagementRiskMember" xlink:type="arc" order="10" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_MarketRiskMember" xlink:label="loc_horzMarketRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzMarketRiskMember" xlink:type="arc" order="20" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_FixedIncomeSecuritiesRiskMember" xlink:label="loc_horzFixedIncomeSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzFixedIncomeSecuritiesRiskMember" xlink:type="arc" order="30" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CollateralizedLoanObligationsRiskMember" xlink:label="loc_horzCollateralizedLoanObligationsRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCollateralizedLoanObligationsRiskMember" xlink:type="arc" order="40" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ActiveTradingRiskMember" xlink:label="loc_horzActiveTradingRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzActiveTradingRiskMember" xlink:type="arc" order="50" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_AuthorizedParticipantConcentrationRiskMember" xlink:label="loc_horzAuthorizedParticipantConcentrationRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzAuthorizedParticipantConcentrationRiskMember" xlink:type="arc" order="60" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_BankLoanRiskMember" xlink:label="loc_horzBankLoanRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzBankLoanRiskMember" xlink:type="arc" order="70" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CashRedemptionRiskMember" xlink:label="loc_horzCashRedemptionRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCashRedemptionRiskMember" xlink:type="arc" order="80" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CommonStockRiskMember" xlink:label="loc_horzCommonStockRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCommonStockRiskMember" xlink:type="arc" order="90" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ConvertibleSecuritiesRiskMember" xlink:label="loc_horzConvertibleSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzConvertibleSecuritiesRiskMember" xlink:type="arc" order="100" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CounterpartyCreditRiskMember" xlink:label="loc_horzCounterpartyCreditRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCounterpartyCreditRiskMember" xlink:type="arc" order="110" />
      <link:loc xlink:type="locator" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditRiskMember" xlink:label="loc_us-gaapCreditRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_us-gaapCreditRiskMember" xlink:type="arc" order="120" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CreditSpreadRiskMember" xlink:label="loc_horzCreditSpreadRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCreditSpreadRiskMember" xlink:type="arc" order="130" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CurrencyRiskMember" xlink:label="loc_horzCurrencyRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCurrencyRiskMember" xlink:type="arc" order="140" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_CybersecurityRiskMember" xlink:label="loc_horzCybersecurityRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzCybersecurityRiskMember" xlink:type="arc" order="150" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_DerivativesRiskMember" xlink:label="loc_horzDerivativesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzDerivativesRiskMember" xlink:type="arc" order="160" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_OptionsRiskMember" xlink:label="loc_horzOptionsRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzOptionsRiskMember" xlink:type="arc" order="170" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_EtfStructureRisksMember" xlink:label="loc_horzEtfStructureRisksMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzEtfStructureRisksMember" xlink:type="arc" order="180" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_FluctuationOfNetAssetValueRiskMember" xlink:label="loc_horzFluctuationOfNetAssetValueRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzFluctuationOfNetAssetValueRiskMember" xlink:type="arc" order="190" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ForeignNonUSInvestmentRiskMember" xlink:label="loc_horzForeignNonUSInvestmentRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzForeignNonUSInvestmentRiskMember" xlink:type="arc" order="200" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_FuturesContractRiskMember" xlink:label="loc_horzFuturesContractRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzFuturesContractRiskMember" xlink:type="arc" order="210" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_GapRiskMember" xlink:label="loc_horzGapRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzGapRiskMember" xlink:type="arc" order="220" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_HedgingTransactionsRiskMember" xlink:label="loc_horzHedgingTransactionsRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzHedgingTransactionsRiskMember" xlink:type="arc" order="230" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_HighYieldRiskMember" xlink:label="loc_horzHighYieldRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzHighYieldRiskMember" xlink:type="arc" order="240" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_IndexRiskMember" xlink:label="loc_horzIndexRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzIndexRiskMember" xlink:type="arc" order="250" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_InvestmentCompaniesExchangeTradedFundsRisksMember" xlink:label="loc_horzInvestmentCompaniesExchangeTradedFundsRisksMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzInvestmentCompaniesExchangeTradedFundsRisksMember" xlink:type="arc" order="260" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_IssuerSpecificRiskMember" xlink:label="loc_horzIssuerSpecificRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzIssuerSpecificRiskMember" xlink:type="arc" order="270" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_LeveragingRiskMember" xlink:label="loc_horzLeveragingRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzLeveragingRiskMember" xlink:type="arc" order="280" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_LiquidityRiskMember" xlink:label="loc_horzLiquidityRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzLiquidityRiskMember" xlink:type="arc" order="290" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_MarketEventsRiskMember" xlink:label="loc_horzMarketEventsRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzMarketEventsRiskMember" xlink:type="arc" order="300" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_MlpRiskMember" xlink:label="loc_horzMlpRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzMlpRiskMember" xlink:type="arc" order="310" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_MortgageBackedAndAssetBackedSecuritiesRiskMember" xlink:label="loc_horzMortgageBackedAndAssetBackedSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzMortgageBackedAndAssetBackedSecuritiesRiskMember" xlink:type="arc" order="320" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_OddLotPricingRiskMember" xlink:label="loc_horzOddLotPricingRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzOddLotPricingRiskMember" xlink:type="arc" order="330" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_PortfolioTurnoverRiskMember" xlink:label="loc_horzPortfolioTurnoverRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzPortfolioTurnoverRiskMember" xlink:type="arc" order="340" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_PrepaymentAndExtensionRiskMember" xlink:label="loc_horzPrepaymentAndExtensionRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzPrepaymentAndExtensionRiskMember" xlink:type="arc" order="350" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_RegulatoryRiskMember" xlink:label="loc_horzRegulatoryRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzRegulatoryRiskMember" xlink:type="arc" order="360" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_SectorRiskMember" xlink:label="loc_horzSectorRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzSectorRiskMember" xlink:type="arc" order="370" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_SecuritiesLendingRiskMember" xlink:label="loc_horzSecuritiesLendingRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzSecuritiesLendingRiskMember" xlink:type="arc" order="380" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_UnderlyingFundRiskMember" xlink:label="loc_horzUnderlyingFundRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzUnderlyingFundRiskMember" xlink:type="arc" order="390" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_USGovernmentSecuritiesRiskMember" xlink:label="loc_horzUSGovernmentSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzUSGovernmentSecuritiesRiskMember" xlink:type="arc" order="400" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ValuationRiskMember" xlink:label="loc_horzValuationRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzValuationRiskMember" xlink:type="arc" order="410" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_VariableOrFloatingRateSecuritiesRiskMember" xlink:label="loc_horzVariableOrFloatingRateSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzVariableOrFloatingRateSecuritiesRiskMember" xlink:type="arc" order="420" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_VolatilityRiskMember" xlink:label="loc_horzVolatilityRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzVolatilityRiskMember" xlink:type="arc" order="430" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_EquityRiskMember" xlink:label="loc_horzEquityRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzEquityRiskMember" xlink:type="arc" order="440" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_FocusRiskMember" xlink:label="loc_horzFocusRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzFocusRiskMember" xlink:type="arc" order="450" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_LargeCapSecuritiesRiskMember" xlink:label="loc_horzLargeCapSecuritiesRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzLargeCapSecuritiesRiskMember" xlink:type="arc" order="460" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_ForwardAndFuturesContractRiskMember" xlink:label="loc_horzForwardAndFuturesContractRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzForwardAndFuturesContractRiskMember" xlink:type="arc" order="470" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_InvestmentCompaniesExchangeTradedFundsRiskMember" xlink:label="loc_horzInvestmentCompaniesExchangeTradedFundsRiskMember" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefAllRisksMember" xlink:to="loc_horzInvestmentCompaniesExchangeTradedFundsRiskMember" xlink:type="arc" order="480" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/CoregistrantOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/SeriesOnly">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain" xlink:label="loc_deiEntityDomain" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_S000101854Member" xlink:label="loc_horzS000101854Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityDomain" xlink:to="loc_horzS000101854Member" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_S000101853Member" xlink:label="loc_horzS000101853Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_deiEntityDomain" xlink:to="loc_horzS000101853Member" xlink:type="arc" order="10" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/ClassOnly">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_ShareClassDomain" xlink:label="loc_oefShareClassDomain" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_C000272171Member" xlink:label="loc_horzC000272171Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefShareClassDomain" xlink:to="loc_horzC000272171Member" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_C000272170Member" xlink:label="loc_horzC000272170Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefShareClassDomain" xlink:to="loc_horzC000272170Member" xlink:type="arc" order="10" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/rr/role/PerformanceMeasureOnly">
      <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/oef/2026/oef-2026.xsd#oef_PerformanceMeasureDomain" xlink:label="loc_oefPerformanceMeasureDomain" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_Index1Member" xlink:label="loc_horzIndex1Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefPerformanceMeasureDomain" xlink:to="loc_horzIndex1Member" xlink:type="arc" order="0" />
      <link:loc xlink:type="locator" xlink:href="horz-20260624.xsd#horz_Index2Member" xlink:label="loc_horzIndex2Member" />
      <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_oefPerformanceMeasureDomain" xlink:to="loc_horzIndex2Member" xlink:type="arc" order="10" />
    </link:definitionLink>
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/HoldingAssetCategoryOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/BroadBasedIndexOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/AdditionalIndexOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/IndustrySectorOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/GeographicRegionOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/CreditQualityOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/MaturityOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/Other1CategoryOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/Other2CategoryOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/LargestHoldingOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/SalesLoadOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/HoldingMeasureOnly" />
    <link:definitionLink xlink:type="extended" xlink:role="http://xbrl.sec.gov/oef/role/ValueMeasureOnly" />
</link:linkbase>
