Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in QSI held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 13.4M | $10.4M | +2.8% | 6.781% | 0.00% |
| 2 | VANGUARD CAPITAL MANAGEMENT LLC | 7.0M | $5.4M | — | 3.550% | 0.00% |
| 3 | ARK Investment Management LLC | 6.9M | $5.3M | -2.0% | 3.477% | 0.04% |
| 4 | Amova Asset Management Americas, Inc. | 4.4M | $3.4M | -6.4% | 2.220% | 0.05% |
| 5 | Sumitomo Mitsui Trust Group, Inc. | 4.4M | $3.4M | -6.4% | 2.220% | 0.00% |
| 6 | GEODE CAPITAL MANAGEMENT, LLC | 3.8M | $3.0M | -6.8% | 1.939% | 0.00% |
| 7 | STATE STREET CORP | 3.8M | $2.9M | +5.8% | 1.906% | 0.00% |
| 8 | AQR CAPITAL MANAGEMENT LLC | 2.4M | $1.9M | +2659.5% | 1.209% | 0.00% |
| 9 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 1.9M | $1.5M | -32.1% | 0.981% | 0.00% |
| 10 | UBS Group AG | 1.7M | $1.3M | +17.5% | 0.861% | 0.00% |
| 11 | VANGUARD PORTFOLIO MANAGEMENT LLC | 1.5M | $1.2M | — | 0.769% | 0.00% |
| 12 | NORTHERN TRUST CORP | 1.3M | $976K | -42.9% | 0.637% | 0.00% |
| 13 | VANGUARD FIDUCIARY TRUST CO | 1.1M | $865K | — | 0.565% | 0.00% |
| 14 | Fosun International Ltd | 744K | $576K | 0.0% | 0.376% | 0.14% |
| 15 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 458K | $354K | -2.3% | 0.231% | 0.00% |
| 16 | Nuveen, LLC | 451K | $349K | +0.9% | 0.228% | 0.00% |
| 17 | GOLDMAN SACHS GROUP INC | 444K | $344K | +14.8% | 0.225% | 0.00% |
| 18 | Invesco Ltd. | 407K | $315K | +1.0% | 0.206% | 0.00% |
| 19 | XTX Topco Ltd | 389K | $301K | -15.7% | 0.197% | 0.01% |
| 20 | ALLIANCEBERNSTEIN L.P. | 272K | $299K | 0.0% | 0.138% | 0.00% |
| 21 | Bank of New York Mellon Corp | 383K | $297K | -5.7% | 0.194% | 0.00% |
| 22 | IEQ CAPITAL, LLC | 358K | $277K | — | 0.181% | 0.00% |
| 23 | Knollwood Investment Advisory, LLC | 300K | $232K | 0.0% | 0.152% | 0.02% |
| 24 | IQ EQ FUND MANAGEMENT (IRELAND) Ltd | 292K | $226K | +15.0% | 0.148% | 0.02% |
| 25 | GROUP ONE TRADING LLC | 284K | $220K | +15.5% | 0.144% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in QSI — a direct measure of their conviction.
Filings activity in QSI during Q1 2026, grouped by how each filer changed its position.
Institutions that opened a new QSI position in Q1 2026
Institutions that fully closed their QSI position in Q1 2026
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 158 | +17% | 20.35% | 10.70 pp | $50M | 34% |
| Q4 2025 | 135 | +11% | 31.05% | 7.72 pp | $76M | 20% |
| Q3 2025 | 122 | 6.9% | 38.77% | 28.05 pp | $94M | 25% |
| Q2 2025 | 131 | 2.2% | 66.82% | +29.91 pp | $125M | +81% |
| Q1 2025 | 134 | +13% | 36.91% | 39.94 pp | $69M | 52% |
| Q4 2024 | 119 | +12% | 76.85% | +52.66 pp | $144M | +218% |
| Q3 2024 | 106 | +8.2% | 24.19% | 5.35 pp | $45M | 18% |
| Q2 2024 | 98 | — | 29.54% | — | $55M | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying QSI stock.
Based on Q1 2026 13F filings, institutional ownership of Quantum-Si incorporated stands at 20.3%, held across 158 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of QSI, with approximately 13,414,949 shares worth $0.01B as of Q1 2026.
Yes — 2 widely-followed marquee investors appear among the top 25 institutional holders of QSI, including ARK Investment Management LLC, SUSQUEHANNA INTERNATIONAL GROUP, LLP.
Our composite Smart Money Score for QSI is 50 out of 100 (Neutral). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
38 institutions opened new positions in QSI during Q1 2026, while 19 fully exited. 11 added to existing positions and 98 trimmed.
QSI institutional ownership fell by 10.70 percentage points quarter-over-quarter, with a net change of +23 holders.
The top 10 institutions account for 77.8% of all reported 13F value in QSI, and the top 25 account for 91.5%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Quantum-Si incorporated (QSI) Institutional Ownership