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, Q4 2025
Institutional positions in Spero Therapeutics, Inc. as of Dec 31, 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
- 56
- +10 vs. Q3 2025
- Shares held
- 21.1M
- +9.85M (+87.4%) vs. Q3 2025
- Total value
- $49.2M
- +$28.0M (+132.3%) vs. Q3 2025
- New holders
- 16
- 14 more added
- Sold out
- 6
- 12 more reduced
1 institution that held it in Q3 2025 haven't filed for Q4 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q3 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, Q4 2025
Shares, value and share of portfolio for each institution holding Spero Therapeutics, Inc.; share changes are against Q3 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| GSK plc | 9,190,606 | $21.4M | 2.68% | +9,190,606 | New |
| Pfizer Inc | 2,362,348 | $5.50M | 2.33% | 00.0% | Unchanged |
| Vanguard Group Inc | 2,083,462 | $4.85M | 0.00% | +93,607+4.7% | Added |
| Renaissance Technologies LLC | 1,279,522 | $2.98M | 0.00% | −173,243−11.9% | Reduced |
| Alphabet Inc. | 889,979 | $2.07M | 0.08% | 00.0% | Unchanged |
| Anson Funds Management LP | 625,062 | $1.46M | 0.19% | −978,507−61.0% | Reduced |
| Geode Capital Management, LLC | 529,195 | $1.23M | 0.00% | +1,718+0.3% | Added |
| BlackRock, Inc. | 433,616 | $1.01M | 0.00% | −1,152−0.3% | Reduced |
| Citadel Advisors LLC | 397,864 | $927.0K | 0.00% | +397,864 | New |
| Two Sigma Investments, LP | 372,570 | $868.1K | 0.00% | +323,171+654.2% | Added |
| Susquehanna International Group, LLP | 293,700 | $684.3K | 0.00% | +293,700 | New |
| EAM Investors, LLC | 218,084 | $508.1K | 0.06% | −64,361−22.8% | Reduced |
| Two Sigma Advisers, LP | 216,600 | $504.7K | 0.00% | +216,600 | New |
| State Street Corp | 210,151 | $489.7K | 0.00% | +19,200+10.1% | Added |
| Ionic Capital Management LLC | 195,939 | $456.5K | 0.45% | −12,786−6.1% | Reduced |
| Gsa Capital Partners LLP | 178,930 | $417.0K | 0.04% | +72,036+67.4% | Added |
| Intrepid Family Office LLC | 165,000 | $384.4K | 0.37% | +55,000+50.0% | Added |
| Jane Street Group, LLC | 158,344 | $368.9K | 0.00% | +115,356+268.3% | Added |
| SEI Investments Co | 132,010 | $307.6K | 0.00% | +132,010 | New |
| Omers Administration Corp | 131,127 | $305.5K | 0.00% | +131,127 | New |
| Northern Trust Corp | 120,984 | $281.9K | 0.00% | −8,659−6.7% | Reduced |
| Squarepoint Ops LLC | 119,434 | $278.3K | 0.00% | +119,434 | New |
| UBS Group AG | 116,447 | $271.3K | 0.00% | +89,346+329.7% | Added |
| Bridgeway Capital Management, LLC | 114,800 | $267.5K | 0.01% | 00.0% | Unchanged |
| ADAR1 Capital Management, LLC | 113,839 | $265.2K | 0.02% | −1,700−1.5% | Reduced |
| Shay Capital LLC | 60,289 | $140.5K | 0.02% | −3,378−5.3% | Reduced |
| Point72 Asset Management, L.P. | 43,579 | $101.5K | 0.00% | +43,579 | New |
| Quadrature Capital Ltd | 37,799 | $88.1K | 0.00% | +37,799 | New |
| Simplex Trading, LLC | 35,686 | $83.1K | 0.00% | +28,068+368.4% | Added |
| Capital Asset Advisory Services LLC | 32,548 | $81.7K | 0.00% | 00.0% | Unchanged |
| Axxcess Wealth Management, LLC | 32,548 | $75.8K | 0.00% | 00.0% | Unchanged |
| Three Seasons Wealth, LLC | 30,000 | $69.9K | 0.01% | 00.0% | Unchanged |
| Dimensional Fund Advisors LP | 29,768 | $69.0K | 0.00% | +774+2.7% | Added |
| Charles Schwab Investment Management Inc | 28,565 | $66.6K | 0.00% | 00.0% | Unchanged |
| Invesco Ltd. | 24,705 | $57.6K | 0.00% | +2,605+11.8% | Added |
| Millennium Management LLC | 24,107 | $56.2K | 0.00% | +24,107 | New |
| Assenagon Asset Management S.A. | 18,636 | $43.4K | 0.00% | −18,357−49.6% | Reduced |
| Torrey Growth & Income Advisors | 17,025 | $39.7K | 0.01% | +1,250+7.9% | Added |
| XTX Topco Ltd | 15,175 | $35.4K | 0.00% | −18,626−55.1% | Reduced |
| Texas Yale Capital Corp. | 10,000 | $23.3K | 0.00% | 00.0% | Unchanged |
| Tower Research Capital LLC (TRC) | 7,215 | $16.8K | 0.00% | +7,215 | New |
| Jones Financial Companies LLLP | 6,477 | $15.1K | 0.00% | +6,477 | New |
| JPMorgan Chase & Co | 5,373 | $12.5K | 0.00% | +5,137+2,176.7% | Added |
| FNY Investment Advisers, LLC | 5,300 | $12.0K | 0.00% | 00.0% | Unchanged |
| Cullen/Frost Bankers, Inc. | 3,000 | $6.99K | 0.00% | +3,000 | New |
| Bank of America Corp | 744 | $1.73K | 0.00% | +11+1.5% | Added |
| Morgan Stanley | 313 | $729 | 0.00% | −43,065−99.3% | Reduced |
| Advisor Group Holdings, Inc. | 290 | $675 | 0.00% | 00.0% | Unchanged |
| Wells Fargo & Company | 200 | $466 | 0.00% | 00.0% | Unchanged |
| Rockefeller Capital Management L.P. | 200 | $466 | 0.00% | 00.0% | Unchanged |
| US Bancorp | 151 | $352 | 0.00% | 00.0% | Unchanged |
| BNP Paribas Arbitrage, SA | 40 | $93 | 0.00% | 00.0% | Unchanged |
| Citigroup Inc | 17 | $40 | 0.00% | +17 | New |
| SageView Advisory Group, LLC | 17 | $40 | 0.00% | +17 | New |
| Farther Finance Advisors, LLC | 10 | $23 | 0.00% | +10 | New |
| SBI Securities Co., Ltd. | 9 | $21 | 0.00% | −1−10.0% | Reduced |
| Arrowstreet Capital, Limited Partnership | 0 | $0 | 0.00% | −150,516−100.0% | Sold out |
| American Century Companies Inc | 0 | $0 | 0.00% | −40,219−100.0% | Sold out |
| Rangeley Capital, LLC | 0 | $0 | 0.00% | −30,000−100.0% | Sold out |
| Group One Trading, L.P. | 0 | $0 | 0.00% | −16,879−100.0% | Sold out |
| FMR LLC | 0 | $0 | 0.00% | −550−100.0% | Sold out |
| GWM Advisors LLC | 0 | $0 | 0.00% | −100−100.0% | Sold out |
| Cubist Systematic Strategies, LLC | – | – | – | – | Not filed |