SPRO (Spero Therapeutics, Inc. Common Stock)

Insider Trading Activity

Every open-market purchase and sale reported by SPRO officers, directors and 10%+ beneficial owners on SEC Form 4, which must be filed within two business days of the transaction. Sales often reflect scheduled 10b5-1 plans or tax withholding rather than a directional view, so read counts alongside the size and the filer.

Market data may be delayed, incomplete, or inaccurate. Not a recommendation to buy, sell, or hold any security. Verify quotes with your broker before trading. See Terms §17.

Form 4 Filings
50
most recent
Open-Market Buys
0
code P
Sales
13
code S
Reporting Insiders
22
current holders
SPRO — Recent Form 4 Transactions (latest 2026-08-06)
FiledInsiderRole TypeSharesValue
2026-08-06 Debra Zack Chief Medical Officer A
2026-06-25 Milind Deshpande Director A
2026-06-25 Cynthia Smith Director A
2026-06-25 Kathleen Tregoning Director A
2026-06-25 John C Jr Pottage Director A
2026-06-25 FRANK E THOMAS Director A
2026-06-25 Scott Thomas Jackson Director A
2026-06-25 PATRICK V.J.J. VINK Director A
2026-05-06 Esther Rajavelu See Remarks Sell
2026-02-09 Timothy Keutzer Chief Operating Officer Sell
2026-02-09 Esther Rajavelu See Remarks Sell
2026-02-05 Timothy Keutzer Chief Operating Officer MIXED
2026-02-04 Esther Rajavelu See Remarks MIXED
2025-11-12 Esther Rajavelu See Remarks Sell
2025-09-03 Ankit Mahadevia Director Sell
2025-09-03 Timothy Keutzer Chief Operating Officer Sell
2025-06-16 John C Jr Pottage Director A
2025-06-16 PATRICK V.J.J. VINK Director A
2025-06-16 Scott Thomas Jackson Director A
2025-06-16 Milind Deshpande Director A
2025-06-16 Kathleen Tregoning Director A
2025-06-16 Cynthia Smith Director A
2025-06-16 FRANK E THOMAS Director A
2025-06-16 Ankit Mahadevia Director A
2025-05-06 Esther Rajavelu See Remarks A
2025-02-05 Esther Rajavelu CFO & CBO MIXED
2025-02-05 Ankit Mahadevia Director Sell
2025-02-05 Sath Shukla CEO & President MIXED
2025-02-05 Timothy Keutzer Chief Operating Officer MIXED
2024-11-12 Esther Rajavelu CFO & CBO Sell
2024-08-29 Timothy Keutzer Chief Operating Officer Sell
2024-08-29 Ankit Mahadevia Director Sell
2024-08-29 Sath Shukla CEO & President Sell
2024-08-06 Sath Shukla CEO and President Sell
2024-05-30 Milind Deshpande Director A
2024-05-30 Cynthia Smith Director A
2024-05-30 PATRICK V.J.J. VINK Director A
2024-05-30 Scott Thomas Jackson Director A
2024-05-30 Kathleen Tregoning Director A
2024-05-30 FRANK E THOMAS Director A
2024-05-30 Ankit Mahadevia Director A
2024-05-30 John C Jr Pottage Director A
2024-02-05 Esther Rajavelu See Remarks A
2024-02-05 Ankit Mahadevia Director Sell
2024-02-05 TAMARA L JOSEPH Chief Legal Officer MIXED
2024-02-05 Sath Shukla CEO and President MIXED
2024-02-05 KAMAL HAMED Chief Medical Officer MIXED
2024-02-05 Timothy Keutzer Chief Operating Officer MIXED
2024-01-04 Kathleen Tregoning Director A
2023-11-15 Esther Rajavelu See Remarks A
SPRO — Current Insider Holders
InsiderRole Shares HeldValue
10%+ Owner 5,321,231
10%+ Owner 3,985,719
Director 1,979,557
10%+ Owner 1,934,006
CEO & President 1,892,216
Director 1,425,435
See Remarks 986,851
Director 877,489
Chief Medical Officer 816,192
Chief Operating Officer 742,506
Director 703,294
Chief Legal Officer 562,521
Chief Medical Officer 162,311
Director 101,454
Director 85,000
Director 85,000
Director 85,000
Director 85,000
Director 85,000
Director 85,000
Chief Operating Officer 63,581
Chief Medical Officer 62,081
How to read Form 4 activity

Form 4 reports a change in beneficial ownership by an officer, director or 10%+ holder, and must be filed within two business days of the transaction — so this is close to real time, unlike the 45-day-lagged 13F institutional data.

Transaction codes matter more than the raw buy/sell count. Code P is an open-market purchase — an insider choosing to buy with their own money, which is the signal most research treats as informative. Code S is a sale, but sales are frequently pre-scheduled under a 10b5-1 plan or cover tax withholding on vesting equity, so a run of sales often says nothing directional. Codes A and M are grants and option exercises rather than open-market decisions.

Full filing history and per-insider positions are on the SPRO quote page; the site-wide leaderboard is on the insider transactions hub.