Over the 90-day window ending February 19, 2026, Spero Therapeutics's three dominant insider ownership positions are held by TenPercentOwner Capital Management, Llc Aquilo (3.42Mn shares), Ceo & President Sath Shukla (1.74Mn shares), Officer Esther Rajavelu (1.01Mn shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Capital Management, Llc Aquilo | 3,419,435 | 26 Sep, 2022 | |
| Sath Shukla | Ceo & President | 1,736,883 | 05 Feb, 2025 |
| Esther Rajavelu | Nan | 1,012,091 | 09 Feb, 2026 |
| Kamal Hamed | Chief Medical Officer | 788,117 | 05 Feb, 2024 |
| Timothy Keutzer | Chief Operating Officer | 742,506 | 09 Feb, 2026 |
| Ankit Mahadevia | 703,294 | 02 Sep, 2025 | |
| Tamara L Joseph | Chief Legal Officer | 531,615 | 05 Feb, 2024 |
| Milind Deshpande | 91,454 | 12 Jun, 2025 | |
| Frank E Thomas | 75,000 | 12 Jun, 2025 | |
| Patrick V.J.J. Vink | 75,000 | 12 Jun, 2025 | |
| John C Jr Pottage | 75,000 | 12 Jun, 2025 | |
| Cynthia Smith | 75,000 | 12 Jun, 2025 | |
| Kathleen Tregoning | 75,000 | 12 Jun, 2025 | |
| Scott Thomas Jackson | 75,000 | 12 Jun, 2025 | |
| Cristina Larkin | Chief Operating Officer | 63,581 | 03 Feb, 2022 |
| David A. Melnick | Chief Medical Officer | 62,081 | 03 Feb, 2022 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 06 Feb, 2026 | Timothy Keutzer | Common Stock | D | 18,652 | $2.36 | 742,506 | D | S |
| 06 Feb, 2026 | Esther Rajavelu | Common Stock | D | 37,101 | $2.36 | 1,062,907 | D | S |
| 06 Feb, 2026 | Esther Rajavelu | Common Stock | D | 50,816 | $2.36 | 1,012,091 | D | S |
| 04 Feb, 2026 | Timothy Keutzer | Common Stock | D | 3,471 | $2.24 | 761,158 | D | S |
| 03 Feb, 2026 | Timothy Keutzer | Common Stock | D | 24,224 | $2.14 | 764,629 | D | S |
| 02 Feb, 2026 | Timothy Keutzer | Common Stock | D | 18,891 | $2.20 | 788,853 | D | S |
| 02 Feb, 2026 | Timothy Keutzer | Common Stock | A | 68,000 | $0.00 | 807,744 | D | A |
| 02 Feb, 2026 | Esther Rajavelu | Common Stock | A | 249,000 | $0.00 | 1,118,450 | D | A |
| 02 Feb, 2026 | Esther Rajavelu | Common Stock | D | 18,442 | $2.20 | 1,100,008 | D | S |
| 07 Nov, 2025 | Esther Rajavelu | Common Stock | D | 40,270 | $2.37 | 869,450 | D | S |
| 28 Aug, 2025 | Ankit Mahadevia | Common Stock | D | 6,572 | $1.97 | 703,294 | D | S |
| 28 Aug, 2025 | Timothy Keutzer | Common Stock | D | 1,695 | $1.97 | 739,744 | D | S |
| 28 Aug, 2025 | Timothy Keutzer | - | - | 739,744 | D | |||
| 12 Jun, 2025 | Frank E Thomas | Common Stock | A | 20,000 | $0.00 | 75,000 | D | A |
| 12 Jun, 2025 | John C Jr Pottage | Common Stock | A | 20,000 | $0.00 | 75,000 | D | A |
| 12 Jun, 2025 | John C Jr Pottage | - | - | 75,000 | D | |||
| 12 Jun, 2025 | Milind Deshpande | Common Stock | A | 20,000 | $0.00 | 91,454 | D | A |
| 12 Jun, 2025 | Patrick V.J.J. Vink | Common Stock | A | 20,000 | $0.00 | 75,000 | D | A |
| 12 Jun, 2025 | Scott Thomas Jackson | Common Stock | A | 20,000 | $0.00 | 75,000 | D | A |
| 12 Jun, 2025 | Cynthia Smith | Common Stock | A | 20,000 | $0.00 | 75,000 | D | A |