Flammer Martina M.D. 4

What Happened

• Martina Flammer, M.D., Chief Medical Officer of INSMED (INSM), sold a total of 18,333 shares in open-market transactions on May 13–14, 2026. The disposals broke down as:
  • 4,470 shares on 2026-05-13 at a weighted average price of $112.76 (prices ranged $112.65–$112.85) — proceeds $504,037.
  • 3,384 shares on 2026-05-13 at $116.18 — proceeds $393,153.
  • 10,479 shares on 2026-05-14 at $117.54 — proceeds $1,231,702.
• Total shares sold: 18,333; total proceeds: $2,128,892. These were sales (not purchases) and appear routine.

Key Details

• Transaction dates/prices: May 13, 2026 (4,470 @ ~$112.76 and 3,384 @ $116.18) and May 14, 2026 (10,479 @ $117.54).
• Shares owned after the transactions: Not disclosed in this filing.
• Notable footnotes:
  • F1: Shares were sold to satisfy tax withholding obligations upon RSU vesting and to cover broker fees.
  • F2: The 4,470-share lot reflects a weighted average price; the filer can provide per-price breakdown on request.
  • F3: The May 14 sale (10,479 shares) was effected pursuant to a Rule 10b5-1 trading plan adopted Feb 27, 2025.
• Filing/timeliness: Form 4 was filed May 15, 2026; the filing date is within the standard reporting window for these transactions.

Context

• These were sales to meet tax-withholding obligations tied to RSU vesting (and related fees), not an open expression of conviction via new purchases. The use of a 10b5-1 plan for the May 14 sale indicates that at least part of the selling was pre‑planned in accordance with SEC Rule 10b5-1.