Quantum-Si Inc
QSI- Exchange
- Nasdaq
- Industry
- Measuring & Controlling Devices, NEC
- SEC CIK
- 0001816431
In the last 90 days, Quantum-Si Inc insiders filed 0 open-market purchases and 3 sales; 141 institutions reported holding it in 13F filings for Q2 2026, worth $46.8M in total; ARK Invest is the only superinvestor holding it.
13F holders, Q3 2025
Institutional positions in Quantum-Si Inc as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 125
- −8 vs. Q2 2025
- Shares held
- 64.6M
- +287.5K (+0.4%) vs. Q2 2025
- Total value
- $91.3M
- −$34.8M (−27.6%) vs. Q2 2025
- New holders
- 14
- 43 more added
- Sold out
- 22
- 40 more reduced
2 institutions that held it in Q2 2025 haven't filed for Q3 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q2 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting QSI on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 141 | $46.8M |
| Q1 2026 | 157 | $49.0M |
| Q4 2025 | 135 | $74.3M |
| Q3 2025 | 125 | $91.3M |
| Q2 2025 | 135 | $126.2M |
| Q1 2025 | 137 | $69.3M |
| Q4 2024 | 121 | $144.8M |
| Q3 2024 | 107 | $45.9M |
| Q2 2024 | 99 | $56.1M |
| Q1 2024 | 95 | $104.1M |
| Q4 2023 | 91 | $113.6M |
| Q3 2023 | 96 | $90.5M |
| Q2 2023 | 91 | $78.5M |
| Q1 2023 | 100 | $76.5M |
| Q4 2022 | 105 | $90.9M |
| Q3 2022 | 102 | $130.8M |
| Q2 2022 | 102 | $139.6M |
| Q1 2022 | 92 | $215.0M |
| Q4 2021 | 93 | $370.6M |
| Q3 2021 | 73 | $372.4M |
| Q2 2021 | 72 | $534.9M |
| Q1 2021 | 0 | $0 |
Institutions, Q3 2025
Shares, value and share of portfolio for each institution holding Quantum-Si Inc; share changes are against Q2 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Knollwood Investment Advisory, LLC | 300,000 | $423.0K | 0.04% | 00.0% | Unchanged |
| Bank of America Corp | 348,007 | $490.7K | 0.00% | −117,992−25.3% | Reduced |
| Group One Trading, L.P. | 377,774 | $532.7K | 0.02% | +243,142+180.6% | Added |
| Goldman Sachs Group Inc | 387,151 | $545.9K | 0.00% | −506,949−56.7% | Reduced |
| Bank of New York Mellon Corp | 394,905 | $556.8K | 0.00% | +42,173+12.0% | Added |
| Citadel Advisors LLC | 407,047 | $573.9K | 0.00% | −151,260−27.1% | Reduced |
| Nuveen, LLC | 447,519 | $631.0K | 0.00% | −678,565−60.3% | Reduced |
| Charles Schwab Investment Management Inc | 468,088 | $660.0K | 0.00% | +36,641+8.5% | Added |
| UBS Group AG | 504,859 | $711.9K | 0.00% | −284,711−36.1% | Reduced |
| Two Sigma Investments, LP | 515,852 | $727.4K | 0.00% | −48,590−8.6% | Reduced |
| Royal Bank of Canada | 532,293 | $750.0K | 0.00% | +72,004+15.6% | Added |
| Squarepoint Ops LLC | 613,475 | $865.0K | 0.00% | +613,475 | New |
| Fosun International Ltd | 743,935 | $1.05M | 0.39% | 00.0% | Unchanged |
| Jane Street Group, LLC | 1,610,023 | $2.27M | 0.00% | +1,325,270+465.4% | Added |
| Susquehanna International Group, LLP | 2,041,095 | $2.88M | 0.00% | +1,055,011+107.0% | Added |
| Northern Trust Corp | 2,323,042 | $3.28M | 0.00% | +33,586+1.5% | Added |
| Millennium Management LLC | 2,669,959 | $3.76M | 0.00% | −1,109,300−29.4% | Reduced |
| State Street Corp | 2,817,490 | $3.97M | 0.00% | +61,053+2.2% | Added |
| Geode Capital Management, LLC | 3,747,169 | $5.28M | 0.00% | +299,431+8.7% | Added |
| Sumitomo Mitsui Trust Holdings, Inc. | 5,217,499 | $7.36M | 0.00% | −403,804−7.2% | Reduced |
| Nikko Asset Management Americas, Inc. | 5,217,499 | $7.36M | 0.07% | −403,804−7.2% | Reduced |
| ARK Investment Management LLCSuperinvestorARK Invest | 7,624,042 | $10.7M | 0.06% | −336,694−4.2% | Reduced |
| Vanguard Group Inc | 8,714,507 | $12.3M | 0.00% | +44,846+0.5% | Added |
| BlackRock, Inc. | 11,321,673 | $16.0M | 0.00% | +473,531+4.4% | Added |
| Summit Wealth Group LLC | 2,330 | – | – | +2,330 | New |
| Gsa Capital Partners LLP | 0 | $0 | 0.00% | −284,363−100.0% | Sold out |
| Ameriprise Financial Inc | 0 | $0 | 0.00% | −223,100−100.0% | Sold out |
| Renaissance Technologies LLC | 0 | $0 | 0.00% | −89,200−100.0% | Sold out |
| Sculptor Capital LP | 0 | $0 | 0.00% | −78,200−100.0% | Sold out |
| Axq Capital, LP | 0 | $0 | 0.00% | −57,000−100.0% | Sold out |
| Two Sigma Securities, LLC | 0 | $0 | 0.00% | −37,861−100.0% | Sold out |
| Atom Investors LP | 0 | $0 | 0.00% | −20,803−100.0% | Sold out |
| Kingsview Wealth Management, LLC | 0 | $0 | 0.00% | −20,012−100.0% | Sold out |
| Jefferies Financial Group Inc. | 0 | $0 | 0.00% | −20,000−100.0% | Sold out |
| Cetera Investment Advisers | 0 | $0 | 0.00% | −18,771−100.0% | Sold out |
| Cerity Partners LLC | 0 | $0 | 0.00% | −14,881−100.0% | Sold out |
| HSBC Holdings PLC | 0 | $0 | 0.00% | −13,717−100.0% | Sold out |
| Neuberger Berman Group LLC | 0 | $0 | 0.00% | −13,430−100.0% | Sold out |
| State Board of Administration of Florida Retirement System | 0 | $0 | 0.00% | −12,300−100.0% | Sold out |
| American Century Companies Inc | 0 | $0 | 0.00% | −12,036−100.0% | Sold out |
| Callan Family Office, LLC | 0 | $0 | 0.00% | −10,379−100.0% | Sold out |
| Ground Swell Capital, LLC | 0 | $0 | 0.00% | −10,100−100.0% | Sold out |
| Headlands Technologies LLC | 0 | $0 | 0.00% | −9,322−100.0% | Sold out |
| Raymond James Financial Inc | 0 | $0 | 0.00% | −3,700−100.0% | Sold out |
| FNY Investment Advisers, LLC | 0 | $0 | 0.00% | −4,000−100.0% | Sold out |
| National Bank of Canada | 0 | $0 | 0.00% | −600−100.0% | Sold out |
| The PNC Financial Services Group, Inc. | 0 | $0 | 0.00% | −548−100.0% | Sold out |
| CIBC World Markets Corp | – | – | – | – | Not filed |
| Talon Private Wealth, LLC | – | – | – | – | Not filed |