QSI — QUANTUM SI INC
Reported value held$42.25M
Funds holding (latest)34
SectorIndustrials
Funds holding (Q2 2026)20
Institutional value$22.41M · 25.33M sh
New / Add / Cut / Exit4 / 7 / 9 / 7
Top-5 / Top-10 concentration80.7% / 97.1%
Institutional holdings change
Reducing -21.5%
(-6.94M sh)
Institutional value change
Down -10.0%
As of Q2 2026, 20 SEC-registered investment managers reported holding QSI (QUANTUM SI INC) in their latest 13F filings, with a combined reported value of $22.41M across 25.33M shares. That is -21.5% by share count (-6.94M shares) versus the previous quarter, while reported value moved -10.0%. Ownership is concentrated: the five largest holders account for 80.7% of reported value and the top ten for 97.1%.
Compared with the prior quarter, 4 opened new positions, 7 added to existing stakes, 9 trimmed, 7 exited entirely. 13F holdings are quarter-end snapshots, so these moves reflect positioning as of Q2 2026, not real-time trading.
QSI is classified in the Industrials sector.
All figures on this page are computed from SEC Form 13F quarterly filings. 13F filers disclose long positions of $100,000 or more within 45 days of quarter end; short positions, options overlays and intra-quarter trades are not included, so treat the numbers as a quarterly snapshot of institutional ownership rather than real-time positioning.
Q2 2026 — 20 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| ARK Invest history | 7.17M | $6.34M | 0.04% | Add |
| BlackRock Inc history | 5.23M | $4.62M | 0.00% | Reduce |
| Millennium Management history | 3.13M | $2.77M | 0.00% | New |
| UBS Group AG history | 2.56M | $2.27M | 0.00% | Add |
| AQR Capital Management history | 2.35M | $2.08M | 0.00% | Reduce |
| Geode Capital Management history | 2.24M | $1.98M | 0.00% | Reduce |
| Renaissance Technologies history | 553.87K | $490.18K | 0.00% | Add |
| Goldman Sachs Group history | 476.29K | $421.51K | 0.00% | Add |
| Northern Trust Corp history | 450.53K | $398.72K | 0.00% | Reduce |
| Invesco Ltd history | 443.93K | $392.88K | 0.00% | Add |
| Morgan Stanley history | 323.48K | $286.28K | 0.00% | Add |
| Fidelity Management & Research (FMR) history | 123.77K | $109.53K | 0.00% | Add |
| Charles Schwab Investment Management history | 84.61K | $74.88K | 0.00% | Reduce |
| Bank of America Corp history | 59.59K | $52.73K | 0.00% | Reduce |
| Citadel Advisors history | 44.34K | $39.24K | 0.00% | Reduce |
| Point72 Asset Management history | 39.13K | $34.63K | 0.00% | New |
| BNY Mellon history | 18.80K | $16.64K | 0.00% | Reduce |
| JPMorgan Chase & Co history | 17.07K | $15.18K | 0.00% | New |
| Balyasny Asset Management history | 13.63K | $12.06K | 0.00% | New |
| Citigroup Inc history | 4.66K | $4.12K | 0.00% | Reduce |
Q1 2026 — 23 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| BlackRock Inc history | 13.41M | $10.38M | 0.00% | Add |
| ARK Invest history | 6.88M | $5.32M | 0.04% | Reduce |
| Geode Capital Management history | 3.84M | $2.97M | 0.00% | Reduce |
| AQR Capital Management history | 2.39M | $1.85M | 0.00% | Add |
| UBS Group AG history | 1.70M | $1.32M | 0.00% | Add |
| Northern Trust Corp history | 1.26M | $975.78K | 0.00% | Reduce |
| Charles Schwab Investment Management history | 457.57K | $354.16K | 0.00% | Reduce |
| Goldman Sachs Group history | 444.18K | $343.79K | 0.00% | Add |
| Invesco Ltd history | 406.69K | $314.78K | 0.00% | Add |
| BNY Mellon history | 383.09K | $296.51K | 0.00% | Reduce |
| Citadel Advisors history | 219.55K | $169.93K | 0.00% | Reduce |
| Bank of America Corp history | 161.99K | $125.38K | 0.00% | Reduce |
| Morgan Stanley history | 129.94K | $100.57K | 0.00% | Reduce |
| Deutsche Bank AG history | 119.03K | $91.65K | 0.00% | Hold |
| Renaissance Technologies history | 117.90K | $91.25K | 0.00% | New |
| Wells Fargo & Co history | 63.87K | $49.43K | 0.00% | Reduce |
| Two Sigma Investments history | 52.92K | $40.96K | 0.00% | Reduce |
| Manulife Financial history | 47.45K | $36.73K | 0.00% | Reduce |
| Fidelity Management & Research (FMR) history | 31.97K | $24.74K | 0.00% | Reduce |
| Prudential Financial history | 21.57K | $16.70K | 0.00% | New |
| Citigroup Inc history | 13.31K | $10.30K | 0.00% | Reduce |
| Legal & General Investment Management America history | 12.86K | $9.95K | 0.00% | Hold |
| T. Rowe Price Associates history | 96.49K | $75 | 0.00% | Hold |
Q4 2025 — 25 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| BlackRock Inc history | 13.05M | $14.36M | 0.00% | Add |
| Vanguard Group history | 9.61M | $10.57M | 0.00% | Add |
| ARK Invest history | 7.02M | $7.72M | 0.05% | Reduce |
| Geode Capital Management history | 4.11M | $4.53M | 0.00% | Add |
| Citadel Advisors history | 3.49M | $3.84M | 0.00% | Add |
| Northern Trust Corp history | 2.21M | $2.43M | 0.00% | Reduce |
| UBS Group AG history | 1.45M | $1.59M | 0.00% | Add |
| Two Sigma Investments history | 1.38M | $1.52M | 0.00% | Add |
| Charles Schwab Investment Management history | 468.17K | $514.99K | 0.00% | Hold |
| BNY Mellon history | 406.29K | $446.92K | 0.00% | Add |
| Invesco Ltd history | 402.82K | $443.10K | 0.00% | Add |
| Morgan Stanley history | 399.99K | $439.99K | 0.00% | Add |
| Goldman Sachs Group history | 386.82K | $425.51K | 0.00% | Hold |
| Bank of America Corp history | 258.44K | $284.29K | 0.00% | Reduce |
| Millennium Management history | 191.79K | $210.97K | 0.00% | Reduce |
| Wells Fargo & Co history | 176.13K | $193.75K | 0.00% | Add |
| Deutsche Bank AG history | 119.03K | $130.93K | 0.00% | Add |
| Fidelity Management & Research (FMR) history | 97.92K | $107.72K | 0.00% | Add |
| AQR Capital Management history | 86.69K | $95.36K | 0.00% | Add |
| JPMorgan Chase & Co history | 76.91K | $84.60K | 0.00% | Add |
| Manulife Financial history | 48.37K | $53.21K | 0.00% | Add |
| Citigroup Inc history | 19.78K | $21.75K | 0.00% | Reduce |
| Balyasny Asset Management history | 19.30K | $21.23K | 0.00% | Reduce |
| Legal & General Investment Management America history | 12.86K | $14.15K | 0.00% | Hold |
| T. Rowe Price Associates history | 96.49K | $107 | 0.00% | Add |
Q3 2025 — 27 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| BlackRock Inc history | 11.32M | $15.96M | 0.00% | Add |
| Vanguard Group history | 8.71M | $12.29M | 0.00% | Add |
| ARK Invest history | 7.62M | $10.75M | 0.06% | Reduce |
| Geode Capital Management history | 3.75M | $5.28M | 0.00% | Add |
| Millennium Management history | 2.67M | $3.76M | 0.00% | Reduce |
| Northern Trust Corp history | 2.32M | $3.28M | 0.00% | Add |
| Citadel Advisors history | 1.20M | $1.69M | 0.00% | Reduce |
| Two Sigma Investments history | 515.85K | $727.35K | 0.00% | Reduce |
| UBS Group AG history | 504.86K | $711.85K | 0.00% | Reduce |
| Charles Schwab Investment Management history | 468.09K | $660.00K | 0.00% | Add |
| BNY Mellon history | 394.90K | $556.82K | 0.00% | Add |
| Goldman Sachs Group history | 387.15K | $545.88K | 0.00% | Reduce |
| Bank of America Corp history | 348.01K | $490.69K | 0.00% | Reduce |
| Invesco Ltd history | 295.73K | $416.98K | 0.00% | Add |
| Morgan Stanley history | 271.00K | $382.11K | 0.00% | Reduce |
| Wells Fargo & Co history | 135.95K | $191.69K | 0.00% | Add |
| Deutsche Bank AG history | 112.08K | $158.04K | 0.00% | Add |
| Fidelity Management & Research (FMR) history | 90.52K | $127.63K | 0.00% | Add |
| AQR Capital Management history | 83.82K | $118.19K | 0.00% | Reduce |
| JPMorgan Chase & Co history | 63.28K | $89.22K | 0.00% | Reduce |
| Manulife Financial history | 47.67K | $67.21K | 0.00% | Reduce |
| Citigroup Inc history | 23.67K | $33.38K | 0.00% | Reduce |
| Balyasny Asset Management history | 19.80K | $27.92K | 0.00% | New |
| Legal & General Investment Management America history | 12.86K | $18.13K | 0.00% | Hold |
| Prudential Financial history | 12.85K | $18.12K | 0.00% | Hold |
| Principal Global Investors history | 11.16K | $15.73K | 0.00% | New |
| T. Rowe Price Associates history | 92.03K | $130 | 0.00% | Reduce |
Q2 2025 — 37 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| BlackRock Inc history | 10.85M | $21.26M | 0.00% | Add |
| BlackRock Inc history | 10.85M | $21.26M | 0.00% | Add |
| Vanguard Group history | 8.67M | $16.99M | 0.00% | Add |
| ARK Invest history | 7.96M | $15.60M | 0.11% | Reduce |
| ARK Invest history | 7.96M | $15.60M | 0.11% | Reduce |
| Millennium Management history | 3.78M | $7.41M | 0.00% | Reduce |
| Geode Capital Management history | 3.45M | $6.76M | 0.00% | Add |
| Northern Trust Corp history | 2.29M | $4.49M | 0.00% | Add |
| Citadel Advisors history | 1.33M | $2.61M | 0.00% | Add |
| Citadel Advisors history | 1.33M | $2.61M | 0.00% | Add |
| Goldman Sachs Group history | 894.10K | $1.75M | 0.00% | Add |
| Goldman Sachs Group history | 894.10K | $1.75M | 0.00% | Add |
| UBS Group AG history | 789.57K | $1.55M | 0.00% | Add |
| Two Sigma Investments history | 564.44K | $1.11M | 0.00% | Reduce |
| Two Sigma Investments history | 564.44K | $1.11M | 0.00% | Reduce |
| Bank of America Corp history | 466.00K | $913.36K | 0.00% | Add |
| Charles Schwab Investment Management history | 431.45K | $845.64K | 0.00% | Add |
| BNY Mellon history | 352.73K | $691.35K | 0.00% | Add |
| Morgan Stanley history | 289.91K | $568.23K | 0.00% | Add |
| Morgan Stanley history | 289.91K | $568.23K | 0.00% | Add |
| Invesco Ltd history | 195.45K | $383.08K | 0.00% | Add |
| AQR Capital Management history | 121.70K | $238.54K | 0.00% | Add |
| Wells Fargo & Co history | 101.72K | $199.36K | 0.00% | Add |
| Deutsche Bank AG history | 98.53K | $193.12K | 0.00% | Add |
| Deutsche Bank AG history | 98.53K | $193.12K | 0.00% | Add |
| Renaissance Technologies history | 89.20K | $174.83K | 0.00% | Reduce |
| Renaissance Technologies history | 89.20K | $174.83K | 0.00% | Reduce |
| JPMorgan Chase & Co history | 66.66K | $130.65K | 0.00% | Add |
| JPMorgan Chase & Co history | 66.66K | $130.65K | 0.00% | Add |
| Citigroup Inc history | 49.11K | $96.25K | 0.00% | Reduce |
| Manulife Financial history | 49.08K | $96.20K | 0.00% | Add |
| Fidelity Management & Research (FMR) history | 18.52K | $36.30K | 0.00% | Reduce |
| Fidelity Management & Research (FMR) history | 18.52K | $36.30K | 0.00% | Reduce |
| Legal & General Investment Management America history | 12.86K | $25.21K | 0.00% | Add |
| Prudential Financial history | 12.85K | $25.19K | 0.00% | New |
| PNC Financial Services history | 548 | $1.07K | 0.00% | Add |
| T. Rowe Price Associates history | 120.51K | $237 | 0.00% | Add |
Q1 2025 — 36 funds
| Fund | Shares | Value | Portfolio Weight | Change |
|---|---|---|---|---|
| BlackRock Inc history | 9.44M | $11.33M | 0.00% | Add |
| BlackRock Inc history | 9.44M | $11.33M | 0.00% | Add |
| ARK Invest history | 8.71M | $10.46M | 0.10% | Reduce |
| ARK Invest history | 8.71M | $10.46M | 0.10% | Reduce |
| Vanguard Group history | 6.89M | $8.27M | 0.00% | Add |
| Millennium Management history | 3.93M | $4.72M | 0.00% | New |
| Geode Capital Management history | 2.99M | $3.59M | 0.00% | Add |
| Northern Trust Corp history | 1.02M | $1.23M | 0.00% | Add |
| Citadel Advisors history | 958.00K | $1.15M | 0.00% | Reduce |
| Citadel Advisors history | 958.00K | $1.15M | 0.00% | Reduce |
| Renaissance Technologies history | 871.76K | $1.05M | 0.00% | Add |
| Renaissance Technologies history | 871.76K | $1.05M | 0.00% | Add |
| Two Sigma Investments history | 816.98K | $980.37K | 0.00% | Add |
| Two Sigma Investments history | 816.98K | $980.37K | 0.00% | Add |
| UBS Group AG history | 449.68K | $539.62K | 0.00% | Reduce |
| Goldman Sachs Group history | 441.31K | $529.58K | 0.00% | Reduce |
| Goldman Sachs Group history | 441.31K | $529.58K | 0.00% | Reduce |
| Charles Schwab Investment Management history | 367.44K | $440.93K | 0.00% | Add |
| BNY Mellon history | 294.91K | $353.89K | 0.00% | Add |
| Morgan Stanley history | 287.49K | $344.99K | 0.00% | Reduce |
| Morgan Stanley history | 287.49K | $344.99K | 0.00% | Reduce |
| Invesco Ltd history | 103.66K | $124.39K | 0.00% | Add |
| AQR Capital Management history | 96.04K | $115.25K | 0.00% | Reduce |
| Bank of America Corp history | 88.50K | $106.19K | 0.00% | Reduce |
| Citigroup Inc history | 84.46K | $101.35K | 0.00% | Reduce |
| Wells Fargo & Co history | 83.33K | $100.00K | 0.00% | Add |
| Fidelity Management & Research (FMR) history | 79.62K | $95.55K | 0.00% | Reduce |
| Fidelity Management & Research (FMR) history | 79.62K | $95.55K | 0.00% | Reduce |
| Deutsche Bank AG history | 67.52K | $81.03K | 0.00% | Add |
| Deutsche Bank AG history | 67.52K | $81.03K | 0.00% | Add |
| JPMorgan Chase & Co history | 57.65K | $69.18K | 0.00% | Add |
| JPMorgan Chase & Co history | 57.65K | $69.18K | 0.00% | Add |
| Manulife Financial history | 38.52K | $46.22K | 0.00% | Add |
| Legal & General Investment Management America history | 9.29K | $11.11K | 0.00% | Hold |
| PNC Financial Services history | 489 | $587 | 0.00% | Add |
| T. Rowe Price Associates history | 108.17K | $130 | 0.00% | Reduce |
New Positions (Q2 2026)
- Millennium Management 3.13M sh · $2.77M
- Point72 Asset Management 39.13K sh · $34.63K
- JPMorgan Chase & Co 17.07K sh · $15.18K
- Balyasny Asset Management 13.63K sh · $12.06K
Fully Exited (vs previous quarter)
- Deutsche Bank AG sold 119.03K sh · $91.65K
- Wells Fargo & Co sold 63.87K sh · $49.43K
- Two Sigma Investments sold 52.92K sh · $40.96K
- Manulife Financial sold 47.45K sh · $36.73K
- Prudential Financial sold 21.57K sh · $16.70K
- Legal & General Investment Management America sold 12.86K sh · $9.95K
- T. Rowe Price Associates sold 96.49K sh · $75
Fund Position History — shares by quarter (top 20 funds)
| Fund | Q2 2026 | Q1 2026 | Q4 2025 | Q3 2025 | Q2 2025 | Q1 2025 | Q4 2024 | Q3 2024 | Q2 2024 | Q1 2024 | Q4 2023 | Q3 2023 | Q2 2023 | Q1 2023 | Q4 2022 | Q3 2022 | Q2 2022 | Q1 2022 | Q4 2021 | Q3 2021 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ARK Invest | 7.17M | 6.88M | 7.02M | 7.62M | 7.96M | 8.71M | 8.85M | 11.84M | 12.41M | 12.77M | 15.52M | 14.45M | 12.75M | 11.70M | 11.86M | 13.24M | 13.87M | 13.37M | 13.07M | 12.70M |
| BlackRock Inc | 5.23M | 13.41M | 13.05M | 11.32M | 10.85M | 9.44M | 8.44M | 6.90M | — | — | — | — | — | — | — | — | — | — | — | — |
| Millennium Management | 3.13M | — | 191.79K | 2.67M | 3.78M | 3.93M | — | 150.87K | 374.73K | 189.79K | — | — | — | 39.29K | 11.11K | — | — | 618.29K | — | 208.72K |
| UBS Group AG | 2.56M | 1.70M | 1.45M | 504.86K | 789.57K | 449.68K | 592.11K | 49.17K | 67.23K | 103.16K | 111.19K | 60.23K | 61.99K | 39.63K | 37.17K | 7.71K | 15.50K | 15.69K | 26.05K | 21.23K |
| AQR Capital Management | 2.35M | 2.39M | 86.69K | 83.82K | 121.70K | 96.04K | 102.40K | 25.89K | — | — | — | — | — | — | — | — | 14.36K | 16.43K | — | — |
| Geode Capital Management | 2.24M | 3.84M | 4.11M | 3.75M | 3.45M | 2.99M | 2.37M | 2.32M | 2.17M | 2.13M | 2.12M | 2.02M | 1.86M | 1.73M | 1.69M | 1.61M | 1.59M | 797.21K | 766.91K | 763.92K |
| Renaissance Technologies | 553.87K | 117.90K | — | — | 89.20K | 871.76K | 544.96K | 41.56K | — | — | — | — | 223.26K | 112.86K | 37.56K | — | — | — | — | — |
| Goldman Sachs Group | 476.29K | 444.18K | 386.82K | 387.15K | 894.10K | 441.31K | 1.00M | 242.14K | 189.17K | 93.87K | 106.08K | 169.31K | 466.07K | 402.36K | 402.97K | 396.11K | 406.88K | 787.79K | 525.88K | 163.05K |
| Northern Trust Corp | 450.53K | 1.26M | 2.21M | 2.32M | 2.29M | 1.02M | 841.15K | 801.12K | 782.19K | 822.34K | 824.39K | 822.76K | 778.84K | 742.48K | 771.01K | 772.58K | 774.62K | 164.88K | 168.88K | 144.93K |
| Invesco Ltd | 443.93K | 406.69K | 402.82K | 295.73K | 195.45K | 103.66K | 37.32K | 33.37K | 35.19K | 40.07K | 187.93K | 179.19K | 177.95K | 178.94K | 41.37K | 41.52K | 41.77K | — | — | — |
| Morgan Stanley | 323.48K | 129.94K | 399.99K | 271.00K | 289.91K | 287.49K | 3.48M | 306.25K | 170.53K | 227.67K | 243.28K | 271.07K | 263.10K | 263.53K | 144.76K | 107.76K | 95.40K | 103.02K | 84.54K | 79.41K |
| Fidelity Management & Research (FMR) | 123.77K | 31.97K | 97.92K | 90.52K | 18.52K | 79.62K | 80.32K | 21.11K | 939 | 4.29K | 5.29K | 6.75K | 3.53K | 1.01K | 1.13K | 4.65K | 262 | — | 16 | — |
| Charles Schwab Investment Management | 84.61K | 457.57K | 468.17K | 468.09K | 431.45K | 367.44K | 308.02K | 232.36K | 260.44K | 261.48K | 260.60K | 276.95K | 261.58K | 238.23K | 238.23K | 232.99K | 232.71K | 32.02K | 32.02K | 32.02K |
| Bank of America Corp | 59.59K | 161.99K | 258.44K | 348.01K | 466.00K | 88.50K | 111.87K | 98.69K | 62.41K | 56.80K | 189.82K | 142.48K | 125.24K | 125.32K | 111.90K | 13.04K | 186.53K | 49.19K | 25.55K | 15.05K |
| Citadel Advisors | 44.34K | 219.55K | 3.49M | 1.20M | 1.33M | 958.00K | 1.07M | 154.55K | 280.70K | 198.80K | 309.43K | 245.90K | 213.01K | 137.73K | 364.08K | 309.03K | 448.35K | 203.49K | 170.61K | 104.60K |
| Point72 Asset Management | 39.13K | — | — | — | — | — | — | — | — | — | — | — | — | 30.47K | — | — | — | — | — | — |
| BNY Mellon | 18.80K | 383.09K | 406.29K | 394.90K | 352.73K | 294.91K | 269.81K | 222.41K | 322.46K | 311.65K | 342.38K | 346.96K | 355.76K | 290.93K | 295.65K | 275.97K | 246.85K | 32.20K | 32.20K | 32.20K |
| JPMorgan Chase & Co | 17.07K | — | 76.91K | 63.28K | 66.66K | 57.65K | 44.86K | 45.04K | 43.66K | 42.28K | 69.05K | 92.06K | 81.92K | 3.93K | 55.65K | 58.30K | 54.45K | 14.17K | 10.79K | — |
| Balyasny Asset Management | 13.63K | — | 19.30K | 19.80K | — | — | 13.49K | — | — | — | — | — | — | — | — | — | — | 60.81K | — | — |
| Citigroup Inc | 4.66K | 13.31K | 19.78K | 23.67K | 49.11K | 84.46K | 90.25K | 84.60K | 23.39K | 19.33K | 15.18K | 1.63K | 33.16K | 1.36K | 4.13K | 4.76K | 9.50K | 24.94K | 5.11K | 8.13K |
▲ Bought Low (fund opened/added, stock rose ≥5% next quarter) ▼ Sold High (fund reduced, stock fell ≥5% next quarter)
Drag / scroll to zoom · Default shows the most recent year · Annotations come from quarterly fund actions in 13F filings · Hover a marker for details