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  <xs:element id="ck0001540305_MSCIACWorldIndexexUSANetreflectsnodeductionforfeesexpensesortaxesIndexMember" abstract="true" name="MSCIACWorldIndexexUSANetreflectsnodeductionforfeesexpensesortaxesIndexMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_C000238324Member" abstract="true" name="C000238324Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_BoxSpreadRiskMember" abstract="true" name="BoxSpreadRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DerivativesRiskCounterpartyRiskMember" abstract="true" name="DerivativesRiskCounterpartyRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DerivativesRiskFLEXOptionsCorrelationRiskMember" abstract="true" name="DerivativesRiskFLEXOptionsCorrelationRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DerivativesRiskFLEXOptionsLiquidityRiskMember" abstract="true" name="DerivativesRiskFLEXOptionsLiquidityRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DerivativesRiskFLEXOptionsValuationRiskMember" abstract="true" name="DerivativesRiskFLEXOptionsValuationRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DerivativesTaxRiskMember" abstract="true" name="DerivativesTaxRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_HighPortfolioTurnoverRiskMember" abstract="true" name="HighPortfolioTurnoverRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_U.S.TreasurySecurityRiskMember" abstract="true" name="U.S.TreasurySecurityRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_ICEUSTreasury1to3YearBondTotalReturnIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" abstract="true" name="ICEUSTreasury1to3YearBondTotalReturnIndexreflectsnodeductionforfeesexpensesortaxesIndexMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_C000243096Member" abstract="true" name="C000243096Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_C000254245Member" abstract="true" name="C000254245Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_C000254244Member" abstract="true" name="C000254244Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_DeferredIncomeStrategyRiskMember" abstract="true" name="DeferredIncomeStrategyRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_FixedIncomeSecuritiesRiskCallRiskMember" abstract="true" name="FixedIncomeSecuritiesRiskCallRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="ck0001540305_FixedIncomeSecuritiesRiskDurationRiskMember" abstract="true" name="FixedIncomeSecuritiesRiskDurationRiskMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
