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 | $48.3M |
| Q4 2025 | 56 | $49.2M |
| Q3 2025 | 47 | $21.3M |
| Q2 2025 | 44 | $32.1M |
| Q1 2025 | 38 | $10.9M |
| Q4 2024 | 50 | $16.1M |
| Q3 2024 | 46 | $16.5M |
| Q2 2024 | 48 | $18.0M |
| Q1 2024 | 54 | $23.7M |
| Q4 2023 | 50 | $19.6M |
| Q3 2023 | 54 | $17.2M |
| Q2 2023 | 56 | $20.8M |
| Q1 2023 | 48 | $20.6M |
| Q4 2022 | 60 | $24.6M |
| Q3 2022 | 69 | $39.7M |
| Q2 2022 | 79 | $15.5M |
| Q1 2022 | 100 | $176.1M |
| Q4 2021 | 84 | $316.7M |
| Q3 2021 | 88 | $338.3M |
| Q2 2021 | 89 | $244.2M |
| Q1 2021 | 95 | $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 |
|---|---|---|---|---|---|
| SBI Securities Co., Ltd. | 9 | $21 | 0.00% | −1−10.0% | Reduced |
| Farther Finance Advisors, LLC | 10 | $23 | 0.00% | +10 | New |
| Citigroup Inc | 17 | $40 | 0.00% | +17 | New |
| SageView Advisory Group, LLC | 17 | $40 | 0.00% | +17 | New |
| BNP Paribas Arbitrage, SA | 40 | $93 | 0.00% | 00.0% | Unchanged |
| US Bancorp | 151 | $352 | 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 |
| Advisor Group Holdings, Inc. | 290 | $675 | 0.00% | 00.0% | Unchanged |
| Morgan Stanley | 313 | $729 | 0.00% | −43,065−99.3% | Reduced |
| Bank of America Corp | 744 | $1.73K | 0.00% | +11+1.5% | Added |
| Cullen/Frost Bankers, Inc. | 3,000 | $6.99K | 0.00% | +3,000 | New |
| FNY Investment Advisers, LLC | 5,300 | $12.0K | 0.00% | 00.0% | Unchanged |
| JPMorgan Chase & Co | 5,373 | $12.5K | 0.00% | +5,137+2,176.7% | Added |
| Jones Financial Companies LLLP | 6,477 | $15.1K | 0.00% | +6,477 | New |
| Tower Research Capital LLC (TRC) | 7,215 | $16.8K | 0.00% | +7,215 | New |
| Texas Yale Capital Corp. | 10,000 | $23.3K | 0.00% | 00.0% | Unchanged |
| XTX Topco Ltd | 15,175 | $35.4K | 0.00% | −18,626−55.1% | Reduced |
| Torrey Growth & Income Advisors | 17,025 | $39.7K | 0.01% | +1,250+7.9% | Added |
| Assenagon Asset Management S.A. | 18,636 | $43.4K | 0.00% | −18,357−49.6% | Reduced |
| Millennium Management LLC | 24,107 | $56.2K | 0.00% | +24,107 | New |
| Invesco Ltd. | 24,705 | $57.6K | 0.00% | +2,605+11.8% | Added |
| Charles Schwab Investment Management Inc | 28,565 | $66.6K | 0.00% | 00.0% | Unchanged |
| Dimensional Fund Advisors LP | 29,768 | $69.0K | 0.00% | +774+2.7% | Added |
| Three Seasons Wealth, LLC | 30,000 | $69.9K | 0.01% | 00.0% | Unchanged |
| Axxcess Wealth Management, LLC | 32,548 | $75.8K | 0.00% | 00.0% | Unchanged |
| Capital Asset Advisory Services LLC | 32,548 | $81.7K | 0.00% | 00.0% | Unchanged |
| Simplex Trading, LLC | 35,686 | $83.1K | 0.00% | +28,068+368.4% | Added |
| Quadrature Capital Ltd | 37,799 | $88.1K | 0.00% | +37,799 | New |
| Point72 Asset Management, L.P. | 43,579 | $101.5K | 0.00% | +43,579 | New |
| Shay Capital LLC | 60,289 | $140.5K | 0.02% | −3,378−5.3% | Reduced |
| ADAR1 Capital Management, LLC | 113,839 | $265.2K | 0.02% | −1,700−1.5% | Reduced |
| Bridgeway Capital Management, LLC | 114,800 | $267.5K | 0.01% | 00.0% | Unchanged |
| UBS Group AG | 116,447 | $271.3K | 0.00% | +89,346+329.7% | Added |
| Squarepoint Ops LLC | 119,434 | $278.3K | 0.00% | +119,434 | New |
| Northern Trust Corp | 120,984 | $281.9K | 0.00% | −8,659−6.7% | Reduced |
| Omers Administration Corp | 131,127 | $305.5K | 0.00% | +131,127 | New |
| SEI Investments Co | 132,010 | $307.6K | 0.00% | +132,010 | New |
| Jane Street Group, LLC | 158,344 | $368.9K | 0.00% | +115,356+268.3% | Added |
| Intrepid Family Office LLC | 165,000 | $384.4K | 0.37% | +55,000+50.0% | Added |
| Gsa Capital Partners LLP | 178,930 | $417.0K | 0.04% | +72,036+67.4% | Added |
| Ionic Capital Management LLC | 195,939 | $456.5K | 0.45% | −12,786−6.1% | Reduced |
| State Street Corp | 210,151 | $489.7K | 0.00% | +19,200+10.1% | Added |
| Two Sigma Advisers, LP | 216,600 | $504.7K | 0.00% | +216,600 | New |
| EAM Investors, LLC | 218,084 | $508.1K | 0.06% | −64,361−22.8% | Reduced |
| Susquehanna International Group, LLP | 293,700 | $684.3K | 0.00% | +293,700 | New |
| Two Sigma Investments, LP | 372,570 | $868.1K | 0.00% | +323,171+654.2% | Added |
| Citadel Advisors LLC | 397,864 | $927.0K | 0.00% | +397,864 | New |
| BlackRock, Inc. | 433,616 | $1.01M | 0.00% | −1,152−0.3% | Reduced |
| Geode Capital Management, LLC | 529,195 | $1.23M | 0.00% | +1,718+0.3% | Added |
| Anson Funds Management LP | 625,062 | $1.46M | 0.20% | −978,507−61.0% | Reduced |
| Alphabet Inc. | 889,979 | $2.07M | 0.08% | 00.0% | Unchanged |
| Renaissance Technologies LLC | 1,279,522 | $2.98M | 0.00% | −173,243−11.9% | Reduced |
| Vanguard Group Inc | 2,083,462 | $4.85M | 0.00% | +93,607+4.7% | Added |
| Pfizer Inc | 2,362,348 | $5.50M | 2.33% | 00.0% | Unchanged |
| GSK plc | 9,190,606 | $21.4M | 2.68% | +9,190,606 | New |
| 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 |