Kersten Dirk 4

What Happened

• Dirk Kersten (listed as a Director and a partner in related Forbion entities) sold a total of 10,952 shares of Dyne Therapeutics in two open-market transactions: 8,300 shares for $166,120 (weighted avg $20.01) on April 21, 2026, and 2,652 shares for $53,049 (weighted avg $20.00) on April 22, 2026. Total proceeds were about $219,169. These were sales (not purchases), and were executed under a pre-established Rule 10b5-1 trading plan.

Key Details

• Transaction dates and prices:
  • Apr 21, 2026 — 8,300 shares disposed; weighted avg reported $20.01 (actual sale prices ranged $20.00–$20.08).
  • Apr 22, 2026 — 2,652 shares disposed; weighted avg reported $20.00 (actual sale prices ranged $20.00–$20.02).
• Filing: Form 4 filed Apr 23, 2026 (within the standard reporting window for insider trades).
• Holdings/ownership notes: The shares sold were held directly by ForDyne B.V. Footnotes state that ForDyne is jointly owned by Forbion funds and that Kersten is a partner of the management entities and a member of their investment committees. The filing includes amounts for which related managers may be deemed to have voting/dispositive power (e.g., 2,770,203 and 1,426,370 shares referenced); the reporting person disclaims beneficial ownership except for any pecuniary interest.
• Notable footnotes: trades executed pursuant to a Rule 10b5-1 plan (F1); weighted-average prices and price ranges reported with offers to provide per-price details on request (F2, F5); ownership/control details for institutional holders (F3, F4).

Context

• These sales were carried out under a 10b5-1 plan and by an institutional vehicle (ForDyne/Forbion-related entities) rather than a direct personal timing decision; such planned sales are often routine and do not necessarily indicate management sentiment about the company. The filing is informational and factual — it does not state the reason for the sales.