<SEC-DOCUMENT>0000709283-21-000011.txt : 20210317
<SEC-HEADER>0000709283-21-000011.hdr.sgml : 20210317
<ACCEPTANCE-DATETIME>20210317160718
ACCESSION NUMBER:		0000709283-21-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210311
FILED AS OF DATE:		20210317
DATE AS OF CHANGE:		20210317

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			King Elizabeth
		CENTRAL INDEX KEY:			0001770712

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13449
		FILM NUMBER:		21750608

	MAIL ADDRESS:	
		STREET 1:		C/O QUANTUM CORPORATION
		STREET 2:		224 AIRPORT PARKWAY, SUITE 550
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUANTUM CORP /DE/
		CENTRAL INDEX KEY:			0000709283
		STANDARD INDUSTRIAL CLASSIFICATION:	COMPUTER STORAGE DEVICES [3572]
		IRS NUMBER:				942665054
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		224 AIRPORT PARKWAY
		STREET 2:		SUITE 550
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
		BUSINESS PHONE:		408 944 4000

	MAIL ADDRESS:	
		STREET 1:		224 AIRPORT PARKWAY
		STREET 2:		SUITE 550
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_161601161020656.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-03-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000709283</issuerCik>
        <issuerName>QUANTUM CORP /DE/</issuerName>
        <issuerTradingSymbol>QMCO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001770712</rptOwnerCik>
            <rptOwnerName>King Elizabeth</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUANTUM CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>224 AIRPORT PARKWAY, SUITE 550</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Revenue Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2021-03-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6875</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>310008</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance-Based Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-03-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6875</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-07-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6875.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6875</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Performance-Based Restricted Stock Units were previously reported on July 2, 2020, which vest in two equal components upon the later of achievement of specified levels of the average closing prices of a share of QMCO common stock during any hundred (100) calendar day period, and upon specified service dates, whichever is later. The first achievement date occurred on March 11, 2021, as certified by the leadership and compensation committee of QMCO, resulting in 6,875 units meeting the appropriate performance-based conditions. However, these shares remain subject to time-based vesting conditions and will therefore vest on January 1, 2022, subject to continued employment. These shares are reflected on Table I, and 6,875 units remaining subject to these performance-based and time-based vesting conditions.</footnote>
        <footnote id="F2">Includes 5,977 shares acquired under Quantum Corporation's Employee Stock Purchase Plan on February 5, 2021.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Josie Buensuceso,  Attorney-in-Fact for Elizabeth King</signatureName>
        <signatureDate>2021-03-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
