<?xml version="1.0"?>
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    <periodOfReport>2026-01-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001592386</issuerCik>
        <issuerName>Virtu Financial, Inc.</issuerName>
        <issuerTradingSymbol>VIRT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002080456</rptOwnerCik>
            <rptOwnerName>Simons Aaron Wyatt</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VIRTU FINANCIAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1633 BROADWAY, 41ST FL</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

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                <transactionPricePerShare>
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        <nonDerivativeTransaction>
            <securityTitle>
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            <transactionDate>
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                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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        <nonDerivativeTransaction>
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        </nonDerivativeTransaction>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit</value>
            </securityTitle>
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            <transactionDate>
                <value>2026-01-31</value>
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                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>37500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
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            <exerciseDate>
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            <expirationDate>
                <footnoteId id="F5"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>37500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                    <value>57743</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit</value>
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            <conversionOrExercisePrice>
                <footnoteId id="F6"/>
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            <transactionDate>
                <value>2026-01-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>53125</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
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            <exerciseDate>
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            <expirationDate>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>53125</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110868</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit</value>
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            <conversionOrExercisePrice>
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                <transactionCode>M</transactionCode>
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                <transactionShares>
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                <transactionPricePerShare>
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                    <value>D</value>
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            <exerciseDate>
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            <expirationDate>
                <footnoteId id="F9"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>11782</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>99086</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Non-voting common interest units of Virtu Financial LLC</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F10"/>
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            <exerciseDate>
                <footnoteId id="F10"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F10"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>520184</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>520184</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F11"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">37,500 RSUs were earned as a result of the Issuer's achievement of associated performance objective for 2024 and vested and settled in shares of Class A common stock on January 31, 2026. The RSUs were
granted under the Issuer's Second Amended and Restated 2015 Management Incentive pursuant to the Third Amended and Restated Employment Agreement between the Issuer and Mr. Aaron Simons.</footnote>
        <footnote id="F2">Shares of Class A common stock withheld for tax by the Issuer in accordance with the Issuer's Second Amended and Restated 2015 Management Incentive Plan.</footnote>
        <footnote id="F3">53,125 shares of Class A common stock were earned as a result of the Issuer's achievement of associated performance objective for 2025 vested on January 31, 2026. The shares are granted under the Issuer's Second Amended and Restated 2015 Management Incentive pursuant to the Third Amended and Restated Employment Agreement between the Issuer and Mr. Aaron Simons.</footnote>
        <footnote id="F4">Shares of Class A common stock issued in settlement of vested shares granted under the Issuer's Second Amended and Restated 2015 Management Incentive Plan.</footnote>
        <footnote id="F5">The RSUs vested on January 31, 2026.</footnote>
        <footnote id="F6">53,125 RSUs were earned as a result of the Issuer's achievement of associated performance objective for 2025.  The RSUs were granted under the Issuer's Second Amended and Restated 2015 Management Incentive Plan and pursuant to the Third Amended and Restated Employment Agreement between the Issuer and Mr. Aaron Simons.</footnote>
        <footnote id="F7">The RSUs vest January 31, 2027.</footnote>
        <footnote id="F8">Each RSU is granted under the Issuer's Amended and Restated 2015 Management Incentive Plan and represents a contingent right to receive one share of Class A common stock of the Issuer.</footnote>
        <footnote id="F9">The RSUs vested February 2, 2026.</footnote>
        <footnote id="F10">Pursuant to the terms of the Exchange Agreement, effective as of April 15, 2015, by and among the Issuer, Virtu Financial LLC and the equityholders of Virtu Financial LLC (the &quot;Exchange Agreement&quot;), Virtu Financial Units, together with a corresponding number of shares of Class C Common Stock, may be exchanged for shares of Class A Common Stock, which have one vote per share and economic rights (including rights to dividends and distributions upon liquidation), on a one-for-one basis at the discretion of the holder. The exchange rights under the Exchange Agreement do not expire.</footnote>
        <footnote id="F11">By Virtu Employee Holdco LLC, a holding vehicle through which employees and directors of the Issuer hold vested and unvested Virtu Financial Units and shares of Class C Common Stock. The reporting person disclaims beneficial ownership in such Virtu Financial Units and shares held by Virtu Employee Holdco LLC except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Justin Waldie, as Attorney-in-Fact</signatureName>
        <signatureDate>2026-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
