Arbuckle Stuart A 4

What Happened
Stuart A. Arbuckle, a director of Alnylam Pharmaceuticals (ALNY), was granted a total of 2,112 award units on 2026-05-20: 671 shares represented by restricted stock units (RSUs) and 1,441 shares listed as a derivative award. Both grants show an acquisition price of $0.00 (awards, not open-market purchases). The awards were made under the company’s 2018 Stock Incentive Plan.

Key Details

• Transaction date: 2026-05-20; Form 4 filed: 2026-05-22 (timely within the two-business-day reporting window).
• Awards: 671 RSUs (F1) + 1,441 derivative award units (F2) — total 2,112 units; $0.00 per unit at grant.
• Vesting: Both awards vest in full upon the earlier of the first anniversary of the grant date or earlier retirement/resignation (only if that retirement/resignation occurs no more than 90 days before the first anniversary) — see footnotes F1 and F2.
• Shares owned after transaction: Not specified in the provided Form 4 excerpt.
• Filing timeliness: Reported on 2026-05-22 for a 2026-05-20 grant — appears timely.

Context
RSUs and similar derivative awards are common director compensation and are contingent on continued service (and here may accelerate only under limited retirement/resignation conditions). These grants involve no cash paid by the director; they represent a contingent right to receive shares if and when vesting conditions are met. Grants are informational but do not alone indicate buying or selling sentiment.