David Kirn, President and Chief Executive Officer of 4D Molecular Therapeutics, Inc. (NASDAQ:FDMT), filed a Form 4 on August 21, 2026, reporting the exercise of a stock option and two open-market sales of common stock that occurred on August 19, 2026, all executed under a pre-established Rule 10b5-1 trading plan.

Key Highlights

  • Option exercise: David Kirn acquired 50,000 shares of common stock on August 19, 2026, via exercise of a stock option at an exercise price of $4.14 per share.
  • First sale: Kirn disposed of 43,149 shares at a weighted average price of $15.3566, with individual trades ranging from $14.91 to $15.84.
  • Second sale: Kirn disposed of 25,927 shares at a weighted average price of $16.4173, with individual trades ranging from $15.97 to $16.65.
  • Remaining direct ownership: Following all reported transactions, Kirn directly holds 825,819 shares of common stock.
  • Remaining options: Kirn retains 217,500 shares underlying a stock option with an exercise price of $4.14, expiring March 5, 2035.
  • 10b5-1 plan: All transactions were made pursuant to a Rule 10b5-1 trading plan adopted by Kirn on January 9, 2026.

David Kirn's Option Exercise and Share Sales at 4D Molecular Therapeutics

According to the filing, David Kirn, who serves as both a Director and President and Chief Executive Officer of 4D Molecular Therapeutics, Inc., reported three transactions in the company's common stock on August 19, 2026. The filing was signed by Scott Bizily as Attorney-in-Fact for David Kirn and submitted on August 21, 2026. All three transactions are attributed by the filing to a Rule 10b5-1 trading plan that Kirn adopted on January 9, 2026.

The first transaction was the exercise of 50,000 stock options (coded "M") at an exercise price of $4.14 per share, bringing Kirn's direct beneficial ownership to 894,895 shares at that point. The filing discloses that the underlying option vests as to 1/48th of the shares on each monthly anniversary of March 6, 2025, such that the option becomes fully vested on the fourth anniversary of that vesting commencement date, contingent on Kirn remaining a service provider to the company. The option expires on March 5, 2035.

Kirn then sold 43,149 shares in multiple trades at a weighted average price of $15.3566, reducing his direct holdings to 851,746 shares, and subsequently sold an additional 25,927 shares in multiple trades at a weighted average price of $16.4173, leaving a final direct beneficial ownership of 825,819 shares. The filing notes that full per-trade price detail for each sale block is available upon request to the SEC staff, the issuer, or any security holder. After the reported transactions, Kirn also retains 217,500 shares underlying the same stock option award in Table II.

What Was Disclosed

The filing reports one stock option exercise and two common stock sales by 4D Molecular Therapeutics' CEO David Kirn on August 19, 2026, all conducted under a 10b5-1 plan, leaving him with direct ownership of 825,819 shares and 217,500 remaining option shares.