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.
Q4 2025 vs. Q3 2025
How the institutions holding Spero Therapeutics, Inc. changed between Q3 2025 and Q4 2025.
All holders in Q4 2025All holders in Q3 2025
| Measure | Q3 2025 | Of which not filed for Q4 2025 | Q4 2025 | Change |
|---|---|---|---|---|
| Holders | 47 | 1 | 56 | +10 |
| Shares | 11.3M | 40.8K | 21.1M | +9.85M (+87.4%) |
| Value | $21.3M | $76.8K | $49.2M | +$28.0M (+132.3%) |
1 institution that held it in Q3 2025 haven't filed for Q4 2025 yet. Not filing isn't selling, so the changes leave them out.
New holders (16)
Institutions that held Spero Therapeutics, Inc. at the end of Q4 2025 but not at the end of Q3 2025.
| Institution | Shares | Value | % of portfolio |
|---|---|---|---|
| GSK plc | 9,190,606 | $21.4M | 2.68% |
| Citadel Advisors LLC | 397,864 | $927.0K | 0.00% |
| Susquehanna International Group, LLP | 293,700 | $684.3K | 0.00% |
| Two Sigma Advisers, LP | 216,600 | $504.7K | 0.00% |
| SEI Investments Co | 132,010 | $307.6K | 0.00% |
| Omers Administration Corp | 131,127 | $305.5K | 0.00% |
| Squarepoint Ops LLC | 119,434 | $278.3K | 0.00% |
| Point72 Asset Management, L.P. | 43,579 | $101.5K | 0.00% |
| Quadrature Capital Ltd | 37,799 | $88.1K | 0.00% |
| Millennium Management LLC | 24,107 | $56.2K | 0.00% |
| Tower Research Capital LLC (TRC) | 7,215 | $16.8K | 0.00% |
| Jones Financial Companies LLLP | 6,477 | $15.1K | 0.00% |
| Cullen/Frost Bankers, Inc. | 3,000 | $6.99K | 0.00% |
| Citigroup Inc | 17 | $40 | 0.00% |
| SageView Advisory Group, LLC | 17 | $40 | 0.00% |
| Farther Finance Advisors, LLC | 10 | $23 | 0.00% |
Sold out (6)
Institutions that held Spero Therapeutics, Inc. at the end of Q3 2025 and filed for Q4 2025 without it.
| Institution | Shares, Q3 2025 | Value, Q3 2025 |
|---|---|---|
| Arrowstreet Capital, Limited Partnership | 150,516 | $283.0K |
| American Century Companies Inc | 40,219 | $75.6K |
| Rangeley Capital, LLC | 30,000 | $56.4K |
| Group One Trading, L.P. | 16,879 | $31.7K |
| FMR LLC | 550 | $1.03K |
| GWM Advisors LLC | 100 | $188 |
Not filed for Q4 2025 yet (1)
Institutions that held Spero Therapeutics, Inc. at the end of Q3 2025 and haven't filed a 13F for Q4 2025. Not filing isn't selling, so they aren't counted as sold out.
| Institution | Shares, Q3 2025 | Value, Q3 2025 |
|---|---|---|
| Cubist Systematic Strategies, LLC | 40,845 | $76.8K |