Seres Therapeutics
MCRB
32 hedge funds and large institutions have $40.9M invested in Seres Therapeutics in 2025 Q3 according to their latest regulatory filings, with 9 funds opening new positions, 10 increasing their positions, 7 reducing their positions, and 10 closing their positions.
571% more call options, than puts
Call options by funds: $17.4M | Put options by funds: $2.6M
61% more capital invested
Capital invested by funds: $25.4M → $40.9M (+$15.5M)
43% more repeat investments, than reductions
Existing positions increased: 10 | Existing positions reduced: 7
0% more funds holding in top 10
Funds holding in top 10: 1 → 1 (0)
1.88% less ownership
Funds ownership: 26.17% → 24.28% (-1.9%)
3% less funds holding
Funds holding: 33 → 32 (-1)
10% less first-time investments, than exits
New positions opened: 9 | Existing positions closed: 10
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Marshall Wace
London,
United Kingdom
|
+$546K |
| 2 |
Citadel Advisors
Miami,
Florida
|
+$493K |
| 3 |
SSA
Schonfeld Strategic Advisors
New York
|
+$462K |
| 4 |
JGC
J. Goldman & Co
New York
|
+$431K |
| 5 |
Vanguard Group
Malvern,
Pennsylvania
|
+$316K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Fidelity Investments
Boston,
Massachusetts
|
-$4.26M |
| 2 |
XT
XTX Topco
George Town,
Cayman Islands
|
-$249K |
| 3 |
Squarepoint
New York
|
-$232K |
| 4 |
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
|
-$186K |
| 5 |
TCM
Tang Capital Management
San Diego,
California
|
-$155K |
MCRB Hedge Fund Activity: Q3 2025 in Review
32 of the 7,621 institutional investors tracked by Wall St. Rank reported a position in Seres Therapeutics (MCRB) for Q3 2025, worth a combined $40.9M — up 61% from $25.4M a quarter earlier.
Sellers outnumbered buyers: 10 funds closed out of MCRB and 9 opened new positions — a net loss of 1 holder — while 7 trimmed existing stakes and 10 added.
The largest buyer was Marshall Wace, adding an estimated $546K. The largest seller was Fidelity Investments, cutting an estimated $4.26M.
- 32 institutional investors held Seres Therapeutics (MCRB) as of Q3 2025, down from 33 in Q2 2025.
- Funds reported $40.9M of Seres Therapeutics stock for Q3 2025, up 61% quarter-over-quarter.
- 9 funds opened new Seres Therapeutics positions in Q3 2025 and 10 closed out, a net change of -1 holder.
- The largest Seres Therapeutics buyer in Q3 2025 was Marshall Wace, an estimated $546K added.
- The largest Seres Therapeutics seller in Q3 2025 was Fidelity Investments, an estimated $4.26M sold.
Based on aggregated 13F filings for Q3 2025.