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.
Open-market trades, last 90 days
Open-market purchases (P) and sales (S) by Spero Therapeutics, Inc. insiders, counted by Form 4 filing. Trades with a flagged price and duplicate filings are left out.
- Open-market buys
- 0 filings
- Open-market sells
- 0 filings
- Insiders trading
- 0
- Net value
- $0
- Purchases minus sales
Insider roster
Directors, officers and 10% owners who have filed a Form 4 for Spero Therapeutics, Inc., current and former, most recent filer first. Last reported holding is the position after the last non-derivative trade in their latest filing.
| Name | Title | Last reported holding | Last filing | Filings, past year |
|---|---|---|---|---|
| Zack Debra | Chief Medical Officer | 162,311 | Aug 6, 2026 | 1 |
| Thomas Frank E | Director | 85,000 | Jun 25, 2026 | 1 |
| Pottage John C Jr | Director | 85,000 | Jun 25, 2026 | 1 |
| Deshpande Milind | Director | 101,454 | Jun 25, 2026 | 1 |
| Vink Patrick V.J.J. | Director | 85,000 | Jun 25, 2026 | 1 |
| Jackson Scott Thomas | Director | 85,000 | Jun 25, 2026 | 1 |
| Smith Cynthia | Director | 85,000 | Jun 25, 2026 | 1 |
| Tregoning Kathleen | Director | 85,000 | Jun 25, 2026 | 1 |
| Rajavelu Esther | See Remarks | 986,851 | May 6, 2026 | 4 |
| Keutzer Timothy | Chief Operating Officer | 742,506 | Feb 9, 2026 | 2 |
| Mahadevia Ankit | Director | 703,294 | Sep 3, 2025 | 0 |
| Shukla Sath | CEO & President | 1,736,883 | Feb 5, 2025 | 0 |
| Joseph Tamara L | Chief Legal Officer | 531,615 | Feb 5, 2024 | 0 |
| Hamed Kamal | Chief Medical Officer | 788,117 | Feb 5, 2024 | 0 |
| Aquilo Capital, L.P. | 10% Owner | 3,419,435Indirect | Sep 26, 2022 | 0 |
| Aquilo Capital Management, LLC | 10% Owner | 3,419,435Indirect | Sep 26, 2022 | 0 |
| Larkin Cristina | Chief Operating Officer | 63,581 | Feb 3, 2022 | 0 |
| Melnick David A. | Chief Medical Officer | 62,081 | Feb 3, 2022 | 0 |
| Formela Jean Francois | Director | – | Aug 18, 2021 | 0 |
Insider trades
Each row adds up one type of transaction in one Form 4 filing. Only open-market purchases (P) and sales (S) are shown by default; use the filters to see grants, option exercises and other codes.
| Filed (ET) | Trade date | Filing delay | Insider | Transaction | Shares | Avg price | Value | Holding change | Flags |
|---|---|---|---|---|---|---|---|---|---|
| May 6, 2026 (view filing) | May 4 | 2 days | Rajavelu EstherSee Remarks | SSale | −25.2K | $2.51 | −$63.4K | −2.5%986.9K after |