Poulton Jeffrey V. 4

What Happened
Jeffrey V. Poulton, Chief Financial Officer of Alnylam Pharmaceuticals (ALNY), disposed of 2,468 shares in a series of open‑market sales on March 4, 2026, generating total proceeds of approximately $797,349. The sales were reported as multiple transactions with weighted average prices ranging roughly from $318.27 to $326.21 (individual reported weighted prices included $319.03, $320.01, $320.81, $321.82, $323.01, $323.84, $324.88 and $325.67). According to the filing, these disposals were made pursuant to a mandatory sell‑to‑cover provision to satisfy minimum statutory tax withholding on vested restricted stock units (RSUs) — a routine, tax‑related sale rather than an opportunistic open‑market trade.

Key Details

• Transaction date: March 4, 2026; Form 4 filed March 6, 2026 (filed within the normal two‑business‑day window).
• Breakdown (shares @ price = proceeds): 114 @ $319.03 = $36,369; 109 @ $320.01 = $34,881; 230 @ $320.81 = $73,786; 309 @ $321.82 = $99,442; 374 @ $323.01 = $120,806; 818 @ $323.84 = $264,901; 291 @ $324.88 = $94,540; 223 @ $325.67 = $72,624. Total: 2,468 shares for ~$797,349.
• Primary footnote: F1 — shares automatically sold by the company on behalf of the reporting person under a mandatory sell‑to‑cover provision to cover tax withholding on vested RSUs.
• Other footnotes in the filing (F2–F9) explain that reported prices are weighted averages across multiple transactions within given price ranges; F10 notes shares acquired under the issuer 401(k) matching program (separate item).
• Shares owned after the transactions are not specified in the provided excerpt of the filing.

Context: These sales were executed to satisfy tax withholding on vested RSUs (routine, indicated by the sell‑to‑cover footnote) and therefore are generally considered administrative rather than a market sentiment signal. For investors tracking insider activity, purchases tend to be more informative about confidence; routine sell‑to‑cover transactions are common when equity awards vest.