February 2, 2026 · Form 4 insider transaction
Rajavelu Esther bought 498,000 shares of Spero Therapeutics Inc. at $0.00 per share, a transaction worth N/A. The trade was recorded as grant or award and disclosed on an SEC Form 4, filed 2 days after the transaction.
The shares underlying this option vest as to 25% on February 2, 2027, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date.