Spero Therapeutics
SPRO
56 hedge funds and large institutions have $49.2M invested in Spero Therapeutics in 2025 Q4 according to their latest regulatory filings, with 16 funds opening new positions, 14 increasing their positions, 12 reducing their positions, and 6 closing their positions.
167% more first-time investments, than exits
New positions opened: 16 | Existing positions closed: 6
131% more capital invested
Capital invested by funds: $21.3M → $49.2M (+$27.9M)
19% more funds holding
Funds holding: 47 → 56 (+9)
17.39% more ownership
Funds ownership: 20.1% → 37.49% (+17%)
17% more repeat investments, than reductions
Existing positions increased: 14 | Existing positions reduced: 12
14% less call options, than puts
Call options by funds: $263K | Put options by funds: $306K
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Citadel Advisors
Miami,
Florida
|
+$924K |
| 2 |
Two Sigma Investments
New York
|
+$750K |
| 3 |
Susquehanna International Group
Bala Cynwyd,
Pennsylvania
|
+$682K |
| 4 |
Two Sigma Advisers
New York
|
+$503K |
| 5 |
SEI Investments
Oaks,
Pennsylvania
|
+$307K |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
AFM
Anson Funds Management
Dallas,
Texas
|
-$2.27M |
| 2 |
Renaissance Technologies
New York
|
-$402K |
| 3 |
Arrowstreet Capital
Boston,
Massachusetts
|
-$283K |
| 4 |
EI
EAM Investors
Solana Beach,
California
|
-$149K |
| 5 |
Morgan Stanley
New York
|
-$100K |
SPRO Hedge Fund Activity: Q4 2025 in Review
56 of the 8,223 institutional investors tracked by Wall St. Rank reported a position in Spero Therapeutics (SPRO) for Q4 2025, worth a combined $49.2M — up 131% from $21.3M a quarter earlier.
Buyers outnumbered sellers: 16 funds opened new SPRO positions and 6 closed out — a net gain of 10 holders — while 14 added to existing stakes and 12 trimmed.
The largest buyer was Citadel Advisors, opening a new position worth an estimated $924K. The largest seller was Anson Funds Management, cutting an estimated $2.27M.
- 56 institutional investors held Spero Therapeutics (SPRO) as of Q4 2025, up from 47 in Q3 2025.
- Funds reported $49.2M of Spero Therapeutics stock for Q4 2025, up 131% quarter-over-quarter.
- 16 funds opened new Spero Therapeutics positions in Q4 2025 and 6 closed out, a net change of +10 holders.
- The largest Spero Therapeutics buyer in Q4 2025 was Citadel Advisors, an estimated $924K added.
- The largest Spero Therapeutics seller in Q4 2025 was Anson Funds Management, an estimated $2.27M sold.
Based on aggregated 13F filings for Q4 2025.