Spero Therapeutics, Inc.
SPRO- Exchange
- Nasdaq
- Industry
- Pharmaceutical Preparations
- SEC CIK
- 0001701108
In the last 90 days, Spero Therapeutics, Inc. insiders filed 0 open-market purchases and 1 sale; 59 institutions reported holding it in 13F filings for Q2 2026, worth $47.5M in total; no superinvestor holds it.
13F holders, Q3 2026
Institutional positions in Spero Therapeutics, Inc. as of Sep 30, 2026. 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
Q3 2026 data is still coming in (13F filing deadline: Nov 16, 2026), so these numbers are incomplete.
- Institutional holders
- 32
- +3 vs. Q2 2026
- Shares held
- 17.1M
- +1.45M (+9.3%) vs. Q2 2026
- Total value
- $20.7M
- −$13.9M (−40.2%) vs. Q2 2026
- New holders
- 10
- 8 more added
- Sold out
- 7
- 6 more reduced
30 institutions that held it in Q2 2026 haven't filed for Q3 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q2 2026: 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, Q3 2026
Shares, value and share of portfolio for each institution holding Spero Therapeutics, Inc.; share changes are against Q2 2026.