Dyne Therapeutics, Inc. 4

Dyne Therapeutics CEO & President John Cox sold 2,683 shares of common stock at about $18.33 per share on June 16, 2026 to cover tax withholding on RSU vesting.

On June 16, 2026, Dyne Therapeutics, Inc. CEO & President John Cox automatically sold 2,683 shares of Dyne common stock at a weighted average price of approximately $18.33 per share, for total proceeds of about $49,200, solely to cover tax withholding obligations arising from the vesting of previously granted restricted stock units under a pre-arranged 10b5-1 compliant agreement and not as a discretionary sale. Following the transaction, Cox directly owns 368,151 shares of Dyne common stock, which, using the reported sale price as a proxy, are worth roughly $6.75 million, and he also has indirect holdings of 18,000 shares in each of four separate trusts (72,000 shares total) established for the benefit of his children, in addition to 259,564 unvested RSUs noted in the footnotes.

Filing Facts

CIK

1818794

Ticker

DYN

Form

4

Source Type

sec

Accession

0001498428-26-000002

Alert Tier

5