Spero TherapeuticsSPRO
13F holders, Q3 2025 (September 30)47holders +3
13new positions
11sold out
1famous investor
$1.88avg. 13F price*
At the end of Q3 2025, 47 institutions reported holding Spero Therapeutics Inc. (SPRO) in their 13F filings, up 3 from Q2 2025. 13 opened new positions and 11 sold out. The largest holders were Pfizer Inc ($4.4M), Vanguard Group Inc. ($3.7M) and Anson Funds Management LP ($3.0M). One famous investor held it Jim Simons / Peter Brown (0.0% of Renaissance Technologies's portfolio).
- Company
- Spero Therapeutics Inc.
- CUSIP
- 84833T103
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q2 2025 → Q3 2025
| Institutions | Total Value | |
|---|---|---|
| New Positions | 13 | $1.3M |
| Exits | 11 | $3.8M |
All 13F filers, Q2 2025 → Q3 2025: 1,593,455 shares bought and 1,376,432 shares sold, net +217,023 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 47 holders
| Pfizer Inc | 1.02% | No change | 2,362,348 | $4.4M |
| Vanguard Group Inc. | 0.00% | Add +2.0% | 1,989,855 | $3.7M |
| Anson Funds Management LP | 0.35% | Reduce -0.7% | 1,603,569 | $3.0M |
| Renaissance Technologies | 0.00% | Add +74.6% | 1,452,765 | $2.7M |
| Alphabet Inc. | 0.07% | No change | 889,979 | $1.7M |
| Geode Capital Management, LLC | 0.00% | Add +3.3% | 527,477 | $992K |
| BlackRock, Inc. | 0.00% | No change | 434,768 | $817K |
| Informed Momentum Co LLC | 0.06% | Add +18.1% | 282,445 | $531K |
| Ionic Capital Management LLC | 0.49% | Add +39.1% | 208,725 | $392K |
| State Street Corp. | 0.00% | Add +24.4% | 190,951 | $359K |
| Arrowstreet Capital, Limited Partnership | 0.00% | New | 150,516 | $283K |
| Northern Trust Corp. | 0.00% | Add +28.6% | 129,643 | $244K |
| ADAR1 Capital Management, LLC | 0.02% | Reduce -19.7% | 115,539 | $217K |
| Bridgeway Capital Management, LLC | 0.00% | No change | 114,800 | $216K |
| Intrepid Family Office LLC | 0.19% | New | 110,000 | $207K |
| Gsa Capital Partners LLP | 0.02% | New | 106,894 | $201K |
| Shay Capital LLC | 0.02% | New | 63,667 | $120K |
| Two Sigma Investments, LP | 0.00% | New | 49,399 | $93K |
| Morgan Stanley | 0.00% | Add +370.4% | 43,378 | $82K |
| Jane Street Group, LLC | 0.00% | New | 42,988 | $81K |
| Cubist Systematic Strategies, LLC | 0.00% | Add +50.5% | 40,845 | $77K |
| American Century Companies Inc. | 0.00% | New | 40,219 | $76K |
| Assenagon Asset Management S.A. | 0.00% | New | 36,993 | $70K |
| XTX Topco Ltd | 0.00% | Reduce -2.2% | 33,801 | $64K |
| Capital Asset Advisory Services LLC | 0.00% | No change | 32,548 | $61K |
| Axxcess Wealth Management, LLC | 0.00% | No change | 32,548 | $61K |
| Rangeley Capital, LLC | 0.05% | New | 30,000 | $56K |
| Three Seasons Wealth, LLC | 0.01% | No change | 30,000 | $56K |
| Dimensional Fund Advisors LP | 0.00% | New | 28,994 | $55K |
| Charles Schwab Investment Management Inc. | 0.00% | No change | 28,565 | $54K |
| UBS Group AG | 0.00% | Add +230.7% | 27,101 | $51K |
| Invesco Ltd. | 0.00% | Add +47.6% | 22,100 | $42K |
| Group One Trading LLC | 0.00% | Add +104.9% | 16,879 | $32K |
| Torrey Growth & Income Advisors | 0.01% | — | 15,775 | $30K |
| Texas Yale Capital Corp. | 0.00% | No change | 10,000 | $19K |
| Simplex Trading, LLC | 0.00% | Reduce -74.9% | 7,618 | $14K |
| FNY Investment Advisers, LLC | 0.00% | New | 5,300 | $9K |
| Bank of America Corp. | 0.00% | Reduce -87.0% | 733 | $1K |
| FMR LLC | 0.00% | New | 550 | $1K |
| Osaic Holdings, Inc. | 0.00% | No change | 290 | $545 |
| JPMorgan Chase & Co. | 0.00% | No change | 236 | $444 |
| Wells Fargo & Company | 0.00% | No change | 200 | $376 |
| Rockefeller Capital Management L.P. | 0.00% | New | 200 | $376 |
| US Bancorp \de | 0.00% | No change | 151 | $284 |
| NewEdge Advisors, LLC | 0.00% | No change | 100 | $188 |
| BNP Paribas Financial Markets | 0.00% | No change | 40 | $75 |
| SBI Securities Co., Ltd. | 0.00% | Reduce -83.9% | 10 | $19 |
"% of holder's portfolio" is SPRO's weight in each manager's 13F, not the share of Spero Therapeutics Inc. the manager owns.