Spero Therapeutics, Inc.
SPRO- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001701108
No open-market purchases or sales by Spero Therapeutics, Inc. insiders were filed in the last 90 days; 59 institutions reported holding it in 13F filings for Q2 2026, worth $47.5M in total; no superinvestor holds it.
13F holders, Q3 2025
Institutional positions in Spero Therapeutics, Inc. as of Sep 30, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 47
- +3 vs. Q2 2025
- Shares held
- 11.3M
- +232.8K (+2.1%) vs. Q2 2025
- Total value
- $21.3M
- −$10.9M (−33.8%) vs. Q2 2025
- New holders
- 14
- 12 more added
- Sold out
- 11
- 6 more reduced
Compare with Q2 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting SPRO on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 59 | $47.5M |
| Q1 2026 | 50 | $49.3M |
| Q4 2025 | 56 | $49.2M |
| Q3 2025 | 47 | $21.3M |
| Q2 2025 | 44 | $32.1M |
| Q1 2025 | 38 | $10.9M |
| Q4 2024 | 50 | $16.5M |
| Q3 2024 | 46 | $16.5M |
| Q2 2024 | 48 | $18.0M |
| Q1 2024 | 54 | $23.7M |
| Q4 2023 | 50 | $143.1M |
| Q3 2023 | 54 | $17.2M |
| Q2 2023 | 56 | $20.8M |
| Q1 2023 | 48 | $25.5M |
| Q4 2022 | 60 | $24.6M |
| Q3 2022 | 69 | $39.7M |
| Q2 2022 | 79 | $15.5M |
| Q1 2022 | 100 | $179.6M |
| Q4 2021 | 84 | $318.3M |
| Q3 2021 | 87 | $338.2M |
| Q2 2021 | 88 | $244.1M |
| Q1 2021 | 94 | $273.1M |
Institutions, Q3 2025
Shares, value and share of portfolio for each institution holding Spero Therapeutics, Inc.; share changes are against Q2 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Pfizer Inc | 2,362,348 | $4.44M | 1.02% | 00.0% | Unchanged |
| Vanguard Group Inc | 1,989,855 | $3.74M | 0.00% | +39,474+2.0% | Added |
| Anson Funds Management LP | 1,603,569 | $3.01M | 0.33% | −11,900−0.7% | Reduced |
| Renaissance Technologies LLC | 1,452,765 | $2.73M | 0.00% | +620,600+74.6% | Added |
| Alphabet Inc. | 889,979 | $1.67M | 0.07% | 00.0% | Unchanged |
| Geode Capital Management, LLC | 527,477 | $991.9K | 0.00% | +16,778+3.3% | Added |
| BlackRock, Inc. | 434,768 | $817.4K | 0.00% | 00.0% | Unchanged |
| EAM Investors, LLC | 282,445 | $531.0K | 0.06% | +43,305+18.1% | Added |
| Ionic Capital Management LLC | 208,725 | $392.4K | 0.44% | +58,725+39.2% | Added |
| State Street Corp | 190,951 | $359.0K | 0.00% | +37,500+24.4% | Added |
| Arrowstreet Capital, Limited Partnership | 150,516 | $283.0K | 0.00% | +150,516 | New |
| Northern Trust Corp | 129,643 | $243.7K | 0.00% | +28,812+28.6% | Added |
| ADAR1 Capital Management, LLC | 115,539 | $217.2K | 0.02% | −28,378−19.7% | Reduced |
| Bridgeway Capital Management, LLC | 114,800 | $215.8K | 0.00% | 00.0% | Unchanged |
| Intrepid Family Office LLC | 110,000 | $206.8K | 0.19% | +110,000 | New |
| Gsa Capital Partners LLP | 106,894 | $201.0K | 0.02% | +106,894 | New |
| Shay Capital LLC | 63,667 | $119.7K | 0.02% | +63,667 | New |
| Two Sigma Investments, LP | 49,399 | $92.9K | 0.00% | +49,399 | New |
| Morgan Stanley | 43,378 | $81.5K | 0.00% | +34,157+370.4% | Added |
| Jane Street Group, LLC | 42,988 | $80.8K | 0.00% | +42,988 | New |
| Cubist Systematic Strategies, LLC | 40,845 | $76.8K | 0.00% | +13,705+50.5% | Added |
| American Century Companies Inc | 40,219 | $75.6K | 0.00% | +40,219 | New |
| Assenagon Asset Management S.A. | 36,993 | $69.5K | 0.00% | +36,993 | New |
| XTX Topco Ltd | 33,801 | $63.5K | 0.00% | −750−2.2% | Reduced |
| Capital Asset Advisory Services LLC | 32,548 | $61.2K | 0.00% | 00.0% | Unchanged |
| Axxcess Wealth Management, LLC | 32,548 | $61.2K | 0.00% | 00.0% | Unchanged |
| Three Seasons Wealth, LLC | 30,000 | $56.4K | 0.01% | 00.0% | Unchanged |
| Rangeley Capital, LLC | 30,000 | $56.4K | 0.05% | +30,000 | New |
| Dimensional Fund Advisors LP | 28,994 | $54.9K | 0.00% | +28,994 | New |
| Charles Schwab Investment Management Inc | 28,565 | $53.7K | 0.00% | 00.0% | Unchanged |
| UBS Group AG | 27,101 | $51.0K | 0.00% | +18,907+230.7% | Added |
| Invesco Ltd. | 22,100 | $41.5K | 0.00% | +7,132+47.6% | Added |
| Group One Trading, L.P. | 16,879 | $31.7K | 0.00% | +8,640+104.9% | Added |
| Torrey Growth & Income Advisors | 15,775 | $29.7K | 0.01% | +15,775 | New |
| Texas Yale Capital Corp. | 10,000 | $18.8K | 0.00% | 00.0% | Unchanged |
| Simplex Trading, LLC | 7,618 | $14.0K | 0.00% | −22,704−74.9% | Reduced |
| FNY Investment Advisers, LLC | 5,300 | $9.00K | 0.00% | +5,300 | New |
| Bank of America Corp | 733 | $1.38K | 0.00% | −4,900−87.0% | Reduced |
| FMR LLC | 550 | $1.03K | 0.00% | +550 | New |
| Advisor Group Holdings, Inc. | 290 | $545 | 0.00% | 00.0% | Unchanged |
| JPMorgan Chase & Co | 236 | $444 | 0.00% | 00.0% | Unchanged |
| Wells Fargo & Company | 200 | $376 | 0.00% | 00.0% | Unchanged |
| Rockefeller Capital Management L.P. | 200 | $376 | 0.00% | +200 | New |
| US Bancorp | 151 | $284 | 0.00% | 00.0% | Unchanged |
| GWM Advisors LLC | 100 | $188 | 0.00% | 00.0% | Unchanged |
| BNP Paribas Arbitrage, SA | 40 | $75 | 0.00% | 00.0% | Unchanged |
| SBI Securities Co., Ltd. | 10 | $19 | 0.00% | −52−83.9% | Reduced |
| Schonfeld Strategic Advisors LLC | 0 | $0 | 0.00% | −510,834−100.0% | Sold out |
| Monimus Capital Management, LP | 0 | $0 | 0.00% | −310,908−100.0% | Sold out |
| Stonepine Capital Management, LLC | 0 | $0 | 0.00% | −156,888−100.0% | Sold out |
| Acadian Asset Management LLC | 0 | $0 | 0.00% | −112,889−100.0% | Sold out |
| Citadel Advisors LLC | 0 | $0 | 0.00% | −103,786−100.0% | Sold out |
| Susquehanna International Group, LLP | 0 | $0 | 0.00% | −69,814−100.0% | Sold out |
| Quadrature Capital Ltd | 0 | $0 | 0.00% | −31,205−100.0% | Sold out |
| Royal Bank of Canada | 0 | $0 | 0.00% | −5,739−100.0% | Sold out |
| Raymond James Financial Inc | 0 | $0 | 0.00% | −3,082−100.0% | Sold out |
| Cullen/Frost Bankers, Inc. | 0 | $0 | 0.00% | −2,000−100.0% | Sold out |
| Tower Research Capital LLC (TRC) | 0 | $0 | 0.00% | −603−100.0% | Sold out |