Jackson Scott Thomas 4

What Happened

• Jackson Scott Thomas, a director of Spero Therapeutics (SPRO), received two awards on June 23, 2026: 10,000 restricted stock units (RSUs) and a 20,000-share derivative award (option-like). Both awards were reported at $0.00 per share (no cash paid and no immediate proceeds). These are grants/awards rather than purchases or sales.

Key Details

• Transaction date: June 23, 2026; Form 4 filed June 25, 2026 (appears timely within the standard 2-business-day window).
• Awards: 10,000 RSUs (reported as A) and 20,000 derivative-share award (reported as A) at $0.00 per share.
• Vesting/exercise: RSUs vest on June 23, 2027 subject to continued service (Footnote F1). The 20,000-share derivative award will vest/become exercisable in full on June 23, 2027, subject to continued service as a director (Footnote F2).
• Shares owned after the transaction: not disclosed in the provided filing.
• No 10b5-1 plan, tax-withholding, or immediate sale noted in this filing.

Context

• The RSUs represent the right to receive one share upon vesting next year; the derivative award appears to be an option-style grant that also vests in 2027. Neither award provides immediate liquidity or indicates a purchase/sale in the open market—these are compensation/retention grants common for directors.