<SEC-DOCUMENT>0001140361-26-009612.txt : 20260316
<SEC-HEADER>0001140361-26-009612.hdr.sgml : 20260316
<ACCEPTANCE-DATETIME>20260316161921
ACCESSION NUMBER:		0001140361-26-009612
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260312
FILED AS OF DATE:		20260316
DATE AS OF CHANGE:		20260316

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Keyes Jeffry R.
		CENTRAL INDEX KEY:			0001557736
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-39486
		FILM NUMBER:		26757005

	MAIL ADDRESS:	
		STREET 1:		13950 STOWE DRIVE
		CITY:			POWAY
		STATE:			CA
		ZIP:			92064-8803

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Quantum-Si Inc
		CENTRAL INDEX KEY:			0001816431
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				851388175
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		29 BUSINESS PARK DRIVE
		CITY:			BRANFORD
		STATE:			CT
		ZIP:			06405
		BUSINESS PHONE:		(203) 458-7100

	MAIL ADDRESS:	
		STREET 1:		29 BUSINESS PARK DRIVE
		CITY:			BRANFORD
		STATE:			CT
		ZIP:			06405

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	HighCape Capital Acquisition Corp.
		DATE OF NAME CHANGE:	20200629
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-03-12</periodOfReport>

    <issuer>
        <issuerCik>0001816431</issuerCik>
        <issuerName>Quantum-Si Inc</issuerName>
        <issuerTradingSymbol>QSI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001557736</rptOwnerCik>
            <rptOwnerName>Keyes Jeffry R.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O QUANTUM-SI INCORPORATED</rptOwnerStreet1>
            <rptOwnerStreet2>29 BUSINESS PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>BRANFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06405</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>true</isOfficer>
            <officerTitle>Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-03-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>652803</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1816000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.976</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-03-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>780847</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2036-03-12</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>780847</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>780847</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The grant consists of restricted stock units (&quot;RSUs&quot;). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs shall vest in four equal annual installments beginning on April 20, 2027 until fully vested, subject to continued service through the applicable vesting date.</footnote>
        <footnote id="F2">The shares underlying this option shall vest in equal quarterly installments beginning on June 20, 2026 until fully vested, subject to continued service through the applicable vesting dates.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Christian LaPointe, Ph.D., Attorney-in-Fact.</signatureName>
        <signatureDate>2026-03-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
