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                    <ccc>XXXXXXXX</ccc>
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                <ns2:city>Guilford</ns2:city>
                <ns2:stateOrCountry>CT</ns2:stateOrCountry>
                <ns2:zipCode>06437</ns2:zipCode>
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            <issuerContactPhone>(866) 688-7374</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Marijn Dekkers</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>38th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>29049</noOfUnitsSold>
            <aggregateMarketValue>95306.86</aggregateMarketValue>
            <noOfUnitsOutstanding>141496840</noOfUnitsOutstanding>
            <approxSaleDate>07/28/2023</approxSaleDate>
            <securitiesExchangeName>NASD</securitiesExchangeName>
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        <securitiesToBeSold>
            <securitiesClassTitle>COMMON</securitiesClassTitle>
            <acquiredDate>07/28/2023</acquiredDate>
            <natureOfAcquisitionTransaction>Stock Option Exercise</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>ISSUER</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>29049</amountOfSecuritiesAcquired>
            <paymentDate>07/28/2023</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
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                <address>
                    <ns2:street1>530 Old Whitfield Street</ns2:street1>
                    <ns2:city>Guilford</ns2:city>
                    <ns2:stateOrCountry>CT</ns2:stateOrCountry>
                    <ns2:zipCode>06437</ns2:zipCode>
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            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>07/19/2023</saleDate>
            <amountOfSecuritiesSold>30831</amountOfSecuritiesSold>
            <grossProceeds>112240.26</grossProceeds>
        </securitiesSoldInPast3Months>
        <noticeSignature>
            <noticeDate>07/28/2023</noticeDate>
            <planAdoptionDates/>
            <signature>/s/ Marijn Dekkers</signature>
        </noticeSignature>
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144
0001216068
XXXXXXXX
LIVE
0001816431
QUANTUM-SI INCORPORATED
001-39486
530 Old Whitfield Street
Guilford
CT
06437
(866) 688-7374
Marijn Dekkers
Director
Common
Morgan Stanley Smith Barney LLC
1 New York Plaza
38th Floor
New York
NY
10004
29049
95306.86
141496840
07/28/2023
NASD
COMMON
07/28/2023
Stock Option Exercise
ISSUER
N
29049
07/28/2023
Cash
N
Marijn Dekkers
530 Old Whitfield Street
Guilford
CT
06437
Common
07/19/2023
30831
112240.26
07/28/2023
/s/ Marijn Dekkers