Form4insider filings, from the source

Company · CIK 0001701108 · SIC 2834 — Pharmaceutical Preparations · Nasdaq

Spero Therapeutics, Inc. · SPRO

Insider activity reported against this company. All insider holders · On EDGAR ↗

1M3M6M1Y2YAll datashares as filed — not split-adjusted

Reported at this company — common stock

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Aug 3, 2026 AForm 4 →Aug 6, 6:49 pm EDTDebra ZackChief Medical Officer162,311——162,311—10b5-1 late

Reported at this company — derivatives (options, RSUs, warrants)

TradeReported (ET)InsiderSharesAvg priceTotalOwned afterΔ stakeFlags
Aug 3, 2026 AForm 4 →Aug 6, 6:49 pm EDTDebra ZackChief Medical Officer324,675——324,675—10b5-1 late