Dianthus (DNTH) Director Read Simon Exercises Options, Sells Shares

What Happened Read Simon, a director of Dianthus Therapeutics (DNTH), exercised options to acquire 2,778 shares at an exercise price of $18.36 per share (cost $51,004) on August 19, 2026, and sold those 2,778 shares in an open market transaction the same day for a weighted average price of $117.55 per share (total proceeds $326,554). The filing also reports the derivative (the option) was converted/terminated in connection with the exercise.

Key Details

• Date of transactions: 2026-08-19.
• Exercise: 2,778 shares acquired at $18.36 each — total cost $51,004.
• Sale: 2,778 shares sold at a weighted average price of $117.55 — total proceeds $326,554. Sales occurred at prices ranging $117.01–$117.66 (see footnote).
• Derivative: Option reported as converted/terminated (disposed) at $0 in the filing, reflecting the exercise.
• Plan/authorization: Sale was effected pursuant to a Rule 10b5-1 trading plan adopted May 8, 2026.
• Vesting note: The option’s underlying shares vest one-third on each of the first three anniversaries of the grant (per footnote).
• Shares owned after transaction: Not specified in this Form 4.
• Filing timeliness: Form 4 filed on 2026-08-19 (same day as transactions).

Context This was an exercise of options followed by an immediate sale of the acquired shares under a pre-established 10b5-1 plan (often structured to automate sales and avoid timing issues). The filing is factual and does not indicate the insider’s motive.