<SEC-DOCUMENT>0001628280-19-012109.txt : 20191002
<SEC-HEADER>0001628280-19-012109.hdr.sgml : 20191002
<ACCEPTANCE-DATETIME>20191002161207
ACCESSION NUMBER:		0001628280-19-012109
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20191001
FILED AS OF DATE:		20191002
DATE AS OF CHANGE:		20191002

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Daunt John
		CENTRAL INDEX KEY:			0001774667

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51813
		FILM NUMBER:		191132358

	MAIL ADDRESS:	
		STREET 1:		C/O 6931 ARLINGTON ROAD
		STREET 2:		SUITE 200
		CITY:			BETHESDA
		STATE:			MD
		ZIP:			20814

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIQUIDITY SERVICES INC
		CENTRAL INDEX KEY:			0001235468
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		IRS NUMBER:				522209244
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		6931 ARLINGTON ROAD
		STREET 2:		SUITE 200
		CITY:			BETHESDA
		STATE:			MD
		ZIP:			20814
		BUSINESS PHONE:		2024676868

	MAIL ADDRESS:	
		STREET 1:		6931 ARLINGTON ROAD
		STREET 2:		SUITE 200
		CITY:			BETHESDA
		STATE:			MD
		ZIP:			20814
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_157004710386124.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
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<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-10-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001235468</issuerCik>
        <issuerName>LIQUIDITY SERVICES INC</issuerName>
        <issuerTradingSymbol>LQDT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001774667</rptOwnerCik>
            <rptOwnerName>Daunt John</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LIQUIDITY SERVICES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>6931 ARLINGTON ROAD SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>BETHESDA</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>20814</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, Chief Commercial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
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                <value>Common Stock</value>
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                <directOrIndirectOwnership>
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            <securityTitle>
                <value>Employee Stock Option</value>
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            <exerciseDate>
                <footnoteId id="F7"/>
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            <expirationDate>
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            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        <derivativeTransaction>
            <securityTitle>
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            <conversionOrExercisePrice>
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            <transactionDate>
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                <transactionFormType>4</transactionFormType>
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            <transactionAmounts>
                <transactionShares>
                    <value>12500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F8"/>
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            <expirationDate>
                <value>2019-10-27</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
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            <underlyingSecurity>
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                <underlyingSecurityShares>
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                <underlyingSecurityShares>
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            <expirationDate>
                <value>2028-07-01</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>100000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Grant</value>
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            <exerciseDate>
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            <expirationDate>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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                <underlyingSecurityShares>
                    <value>4834.0</value>
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                <sharesOwnedFollowingTransaction>
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                <footnoteId id="F15"/>
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            <expirationDate>
                <value>2021-10-01</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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                <underlyingSecurityShares>
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                <sharesOwnedFollowingTransaction>
                    <value>4028</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Grant</value>
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                <footnoteId id="F4"/>
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                <footnoteId id="F13"/>
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            <expirationDate>
                <value>2028-12-04</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                <underlyingSecurityShares>
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                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Grant</value>
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                <footnoteId id="F4"/>
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            <exerciseDate>
                <footnoteId id="F16"/>
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            <expirationDate>
                <value>2022-10-01</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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                <sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeHolding>
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            <securityTitle>
                <value>Employee Stock Option</value>
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            <conversionOrExercisePrice>
                <value>6.11</value>
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            <exerciseDate>
                <footnoteId id="F12"/>
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            <expirationDate>
                <value>2028-12-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20800.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Employee Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.11</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F17"/>
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            <expirationDate>
                <value>2022-10-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>20800.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the net issuance of 9,427 shares from the vesting of 12,500 restricted stock units from which the federal and state withholding due at the vesting of such restricted stock units was satisfied by the issuer withholding 3,073 shares.  The reporting person relinquished the shares and the issuer cancelled the shares and returned them to treasury in exchange for remitting federal and state tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.  Shares withheld represent an exempt transaction pursuant to Section 16b-3(e).  No shares were sold by the reporting person.</footnote>
        <footnote id="F2">Represents the net issuance of 1,721 shares from the vesting of 2,283 restricted stock units from which the federal and state withholding due at the vesting of such restricted stock units was satisfied by the issuer withholding 562 shares.  The reporting person relinquished the shares and the issuer cancelled the shares and returned them to treasury in exchange for remitting federal and state tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.  Shares withheld represent an exempt transaction pursuant to Section 16b-3(e).  No shares were sold by the reporting person.</footnote>
        <footnote id="F3">Represents the net issuance of 726 shares from the vesting of 963 restricted stock units from which the federal and state withholding due at the vesting of such restricted stock units was satisfied by the issuer withholding 237 shares.  The reporting person relinquished the shares and the issuer cancelled the shares and returned them to treasury in exchange for remitting federal and state tax withholding obligations of the reporting person resulting from the vesting of restricted stock units.  Shares withheld represent an exempt transaction pursuant to Section 16b-3(e).  No shares were sold by the reporting person.</footnote>
        <footnote id="F4">Each restricted stock unit is the economic equivalent of one share of Liquidity Services, Inc. Common Stock.</footnote>
        <footnote id="F5">Represents the vesting of restricted stock.</footnote>
        <footnote id="F6">Twenty-five percent of this restricted stock grant vested on October 1, 2016 and thereafter 1/4th of the restricted stock grant will vest on October 1 of each year for three years.</footnote>
        <footnote id="F7">This option becomes exercisable, if at all, based on the Issuer's achievement of certain financial milestones.</footnote>
        <footnote id="F8">Twenty-five percent of this restricted stock grant vested on April 1, 2017 and April 1, 2018, and thereafter 1/4th of the restricted stock grant will vest on October 1, 2018, and October 1, 2019.</footnote>
        <footnote id="F9">These options became fully vested on October 1, 2019.</footnote>
        <footnote id="F10">These restricted stock units will vest, if at all, based on the Issuer's achievement of certain financial milestones.</footnote>
        <footnote id="F11">15/48th of this option grant will vest on January 1, 2018 and thereafter 1/48th of the option grant will vest each month for thirty three months.</footnote>
        <footnote id="F12">This option becomes exercisable, if at all, based on total shareholder return (TSR) milestones.  TSR is calculated based on the change in a the issuer's stock price during the performance period, taking into account any dividends paid during that period, which are assumed to be reinvested in the stock.</footnote>
        <footnote id="F13">These restricted stock units vest, if at all, based on total shareholder return (TSR) milestones.  TSR is calculated based on the change in a the issuer's stock price during the performance period, taking into account any dividends paid during that period, which are assumed to be reinvested in the stock.</footnote>
        <footnote id="F14">Twenty-five percent of this restricted stock grant vested on January 1, 2018, October 1, 2018, and October 1, 2019, and thereafter 1/4th of the restricted stock grant will vest on October 1, 2020.</footnote>
        <footnote id="F15">Twenty-five percent of this restricted stock grant vested on April 1, 2019, and thereafter 1/4th of the restricted stock grant will vest on July 1, 2019, October 1, 2020, and October 1, 2021.</footnote>
        <footnote id="F16">Twenty-five percent of this restricted stock grant will vest on January 1, 2020 and thereafter 1/4th of the restricted stock grant will vest on each October 1, 2020, October 1, 2021, and October 1, 2022.</footnote>
        <footnote id="F17">15/48th of this option grant will vest on January 1, 2020 and thereafter 1/48th of the option grant will vest each month for thirty three months.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Mark A. Shaffer, by power of attorney</signatureName>
        <signatureDate>2019-10-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
