<SEC-DOCUMENT>0001758766-21-000064.txt : 20210528
<SEC-HEADER>0001758766-21-000064.hdr.sgml : 20210528
<ACCEPTANCE-DATETIME>20210528155054
ACCESSION NUMBER:		0001758766-21-000064
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210428
FILED AS OF DATE:		20210528
DATE AS OF CHANGE:		20210528

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BUSH WILLIAM JOHN
		CENTRAL INDEX KEY:			0001241516

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39455
		FILM NUMBER:		21979888

	MAIL ADDRESS:	
		STREET 1:		539 BRYANT STREET
		STREET 2:		SUITE 403
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94107

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			STEM, INC.
		CENTRAL INDEX KEY:			0001758766
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
		IRS NUMBER:				264466193
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 ROLLINS ROAD
		CITY:			MILLBRAE
		STATE:			CA
		ZIP:			94030
		BUSINESS PHONE:		(415) 937-7836

	MAIL ADDRESS:	
		STREET 1:		100 ROLLINS ROAD
		CITY:			MILLBRAE
		STATE:			CA
		ZIP:			94030

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Star Peak Energy Transition Corp.
		DATE OF NAME CHANGE:	20200714

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Star Peak Energy Acquisition Corp.
		DATE OF NAME CHANGE:	20181119

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Roaring Fork Acquisition Corp.
		DATE OF NAME CHANGE:	20181109
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>wf-form3_162223143486993.xml
<DESCRIPTION>FORM 3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-04-28</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001758766</issuerCik>
        <issuerName>STEM, INC.</issuerName>
        <issuerTradingSymbol>STEM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001241516</rptOwnerCik>
            <rptOwnerName>BUSH WILLIAM JOHN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 ROLLINS ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILLBRAE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Financial Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>257207</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.67</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2020-11-07</value>
            </exerciseDate>
            <expirationDate>
                <value>2027-05-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>255933.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.41</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2029-10-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>268630.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.81</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2020-12-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2030-12-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>99608.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.81</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2030-12-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>341977.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">25% of the shares underlying the option vest on the first anniversary date, and the remaining shares underlying the option vest in 36 equal monthly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date.</footnote>
        <footnote id="F2">25% of the shares underlying the option vest ratably over a four-year period, subject to the Reporting Person's continuous employment with the Issuer on each such date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>William Bush</signatureName>
        <signatureDate>2021-05-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
