QUANTUM-SI INC (QSI) Institutional Ownership Changes & 13F Activity

QUANTUM-SI INC (QSI). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings. This page analyzes institutional buying and selling activity, new holdings, and sold-out positions among tracked filers. Notable filers include ARK Invest and Renaissance Technologies LLC.

Portfolio quarterNameTypeQuantityRemainingReported stock balance
Q1 2026ARK InvestSell-142,6726,878,899$5,324,268
Q1 2026Renaissance Technologies LLCBuy28,700117,900$91,255
Q4 2025ARK InvestSell-602,4717,021,571$7,723,728
Q3 2025ARK InvestSell-336,6947,624,042$10,749,899
Q2 2025Renaissance Technologies LLCSell-782,55689,200$174,832
Q2 2025ARK InvestSell-752,7657,960,736$15,603,043
Q1 2025Renaissance Technologies LLCBuy326,800871,756$1,046,107
Q1 2025ARK InvestSell-135,1498,713,501$10,456,201
Q4 2024ARK InvestSell-2,993,9598,848,650$23,891,355
Q4 2024Renaissance Technologies LLCBuy503,400544,956$1,471,381
Q3 2024ARK InvestSell-567,32011,842,609$10,447,550
Q3 2024Renaissance Technologies LLCSell-181,70041,556$36,661
Q2 2024ARK InvestSell-358,94712,409,929$13,030,425
Q1 2024ARK InvestSell-2,750,44612,768,876$25,154,686
Q4 2023ARK InvestBuy1,071,10515,519,322$31,193,838
Q3 2023ARK InvestBuy1,693,68614,448,217$23,984,040
Q2 2023ARK InvestBuy1,055,74012,754,531$22,830,610
Q2 2023Renaissance Technologies LLCBuy110,400223,256$400
Q1 2023ARK InvestSell-157,39311,698,791$20,589,872
Q1 2023Renaissance Technologies LLCBuy75,300112,856$199
Q4 2022ARK InvestSell-1,381,60611,856,184$21,696,817
Q4 2022Renaissance Technologies LLCBuy37,55637,556$69
Q3 2022ARK InvestSell-631,29413,237,790$36,404
Q2 2022ARK InvestBuy495,52713,869,084$58,944
Q1 2022ARK InvestBuy306,40713,373,557$62,588
Q4 2021ARK InvestBuy368,76913,067,150$102,838
Q3 2021ARK InvestBuy8,650,07812,698,381$105,904
Q2 2021ARK InvestBuy4,048,3034,048,303$49,632

Frequently asked questions about QSI activity

  • Which institutional owners are buying QSI?

    Institutional owners buying QSI include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.

  • What does "buy" mean in QSI activity?

    "Buy" means an investor increased their reported position in QSI compared to the prior reporting period. This reflects growing exposure to QUANTUM-SI INC (QSI) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).

  • Is institutional interest in QSI increasing?

    Institutional interest in QSI can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.

Related QSI Institutional Insights