11 insiders reported 41 Form 4 transactions for Spero Therapeutics, Inc. (SPRO) over the past 18 months (most recent 2026-06-25). Recent activity: THOMAS FRANK E (Director) Buy 10,000 shares, Pottage John C Jr (Director) Buy 10,000 shares, Deshpande Milind (Director) Buy 10,000 shares, VINK PATRICK V.J.J. (Director) Buy 10,000 shares, Jackson Scott Thomas (Director) Buy 10,000 shares. Source: SEC Form 4.
| Date | Insider | Title | Type | Shares | Value |
|---|---|---|---|---|---|
| 2026-06-25 | THOMAS FRANK E | Director | Buy | 10,000 | $0 |
| 2026-06-25 | Pottage John C Jr | Director | Buy | 10,000 | $0 |
| 2026-06-25 | Deshpande Milind | Director | Buy | 10,000 | $0 |
| 2026-06-25 | VINK PATRICK V.J.J. | Director | Buy | 10,000 | $0 |
| 2026-06-25 | Jackson Scott Thomas | Director | Buy | 10,000 | $0 |
| 2026-06-25 | Smith Cynthia | Director | Buy | 10,000 | $0 |
| 2026-06-25 | Tregoning Kathleen | Director | Buy | 10,000 | $0 |
| 2026-02-09 | Rajavelu Esther | See Remarks | Sell | 37,101 | $87,558 |
| 2026-02-09 | Rajavelu Esther | See Remarks | Sell | 50,816 | $119,926 |
| 2026-02-09 | Keutzer Timothy | Chief Operating Officer | Sell | 18,652 | $44,019 |
| 2026-02-05 | Keutzer Timothy | Chief Operating Officer | Sell | 24,224 | $51,839 |
| 2026-02-05 | Keutzer Timothy | Chief Operating Officer | Sell | 18,891 | $41,560 |
| 2026-02-05 | Keutzer Timothy | Chief Operating Officer | Buy | 68,000 | $0 |
| 2026-02-05 | Keutzer Timothy | Chief Operating Officer | Sell | 3,471 | $7,775 |
| 2026-02-04 | Rajavelu Esther | See Remarks | Buy | 249,000 | $0 |
| 2026-02-04 | Rajavelu Esther | See Remarks | Sell | 18,442 | $40,572 |
| 2025-11-12 | Rajavelu Esther | See Remarks | Sell | 40,270 | $95,440 |
| 2025-09-03 | Mahadevia Ankit | Director | Sell | 6,572 | $12,947 |
| 2025-09-03 | Keutzer Timothy | Chief Operating Officer | Sell | 1,695 | $3,339 |
| 2025-06-16 | Deshpande Milind | Director | Buy | 20,000 | $0 |
| 2025-06-16 | VINK PATRICK V.J.J. | Director | Buy | 20,000 | $0 |
| 2025-06-16 | THOMAS FRANK E | Director | Buy | 20,000 | $0 |
| 2025-06-16 | Mahadevia Ankit | Director | Buy | 20,000 | $0 |
| 2025-06-16 | Jackson Scott Thomas | Director | Buy | 20,000 | $0 |
| 2025-06-16 | Smith Cynthia | Director | Buy | 20,000 | $0 |
Source: SEC Form 4 filings · as of 2026-06-25