Quantum-Si Incorporated
QSI
135 hedge funds and large institutions have $74.3M invested in Quantum-Si Incorporated in 2025 Q4 according to their latest regulatory filings, with 32 funds opening new positions, 38 increasing their positions, 37 reducing their positions, and 19 closing their positions.
68% more first-time investments, than exits
New positions opened: 32 | Existing positions closed: 19
8% more funds holding
Funds holding: 125 → 135 (+10)
8% more call options, than puts
Call options by funds: $1.95M | Put options by funds: $1.81M
3% more repeat investments, than reductions
Existing positions increased: 38 | Existing positions reduced: 37
0.89% less ownership
Funds ownership: 35.4% → 34.52% (-0.89%)
19% less capital invested
Capital invested by funds: $91.5M → $74.3M (-$17.2M)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Citadel Advisors
Miami,
Florida
|
+$3.69M |
| 2 |
BlackRock
New York
|
+$2.82M |
| 3 |
UBS Group
Zurich,
Switzerland
|
+$1.54M |
| 4 |
Vanguard Group
Malvern,
Pennsylvania
|
+$1.45M |
| 5 |
Two Sigma Investments
New York
|
+$1.41M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Millennium Management
New York
|
-$4.03M |
| 2 |
AIM
ARK Investment Management
St. Petersburg,
Florida
|
-$981K |
| 3 |
Squarepoint
New York
|
-$865K |
| 4 |
Royal Bank of Canada
Toronto,
Ontario, Canada
|
-$859K |
| 5 |
NAMA
Nikko Asset Management Americas
New York
|
-$857K |
QSI Hedge Fund Activity: Q4 2025 in Review
135 of the 8,266 institutional investors tracked by Wall St. Rank reported a position in Quantum-Si Incorporated (QSI) for Q4 2025, worth a combined $74.3M — down 19% from $91.5M a quarter earlier.
Buyers outnumbered sellers: 32 funds opened new QSI positions and 19 closed out — a net gain of 13 holders — while 38 added to existing stakes and 37 trimmed.
The largest buyer was Citadel Advisors, adding an estimated $3.69M. The largest seller was Millennium Management, cutting an estimated $4.03M.
- 135 institutional investors held Quantum-Si Incorporated (QSI) as of Q4 2025, up from 125 in Q3 2025.
- Funds reported $74.3M of Quantum-Si Incorporated stock for Q4 2025, down 19% quarter-over-quarter.
- 32 funds opened new Quantum-Si Incorporated positions in Q4 2025 and 19 closed out, a net change of +13 holders.
- The largest Quantum-Si Incorporated buyer in Q4 2025 was Citadel Advisors, an estimated $3.69M added.
- The largest Quantum-Si Incorporated seller in Q4 2025 was Millennium Management, an estimated $4.03M sold.
Based on aggregated 13F filings for Q4 2025.