Director Robert Chess filed a Form 4 with the SEC on August 11, 2026, reporting the exercise of stock options and a same-day sale of common stock in Twist Bioscience Corp (NASDAQ:TWST) on August 7, 2026, pursuant to a Rule 10b5-1 trading plan.

Key Highlights

  • Option exercise: Robert Chess acquired 18,417 shares of common stock via a stock option exercise (transaction code M) on August 7, 2026, at an exercise price of $11.89 per share.
  • Same-day sale: Chess disposed of 18,417 shares (transaction code S) on August 7, 2026, at $110.89 per share.
  • Direct ownership following transactions: Chess directly beneficially owns 21,084 shares of common stock after the reported transactions.
  • Indirect ownership: Chess also holds 42,528 shares indirectly through the Chess 1997 Trust, of which he and his spouse are the sole trustees and sole beneficiaries.
  • 10b5-1 plan: According to the filing, the transactions were effected pursuant to a Rule 10b5-1 trading plan previously adopted by Chess on May 8, 2026.
  • Option now fully exercised: Following the exercise, the derivative security shows 0 stock options remaining beneficially owned directly.

Robert Chess Option Exercise and Share Sale at Twist Bioscience

According to the Form 4 filing, Robert Chess, a director of Twist Bioscience Corp, executed two related transactions on August 7, 2026. He exercised a stock option to acquire 18,417 shares of common stock at an exercise price of $11.89 per share, then sold those same 18,417 shares at $110.89 per share on the same date. The filing indicates both transactions were carried out under a Rule 10b5-1 trading plan that Chess had adopted on May 8, 2026.

The exercised option carried an expiration date of September 13, 2028, and, per the filing, was immediately exercisable at the time of the transaction. The filing describes the original vesting schedule: 10% of the shares subject to the option vested on September 13, 2018; 15% vested on March 24, 2019; and 1/48th of the shares vested on each monthly anniversary thereafter, subject to Chess's continuous service through each vesting date. Following the exercise, the filing reports 0 options remaining in this position.

After the reported transactions, Chess directly holds 21,084 shares of Twist Bioscience common stock. He also holds 42,528 shares indirectly through the Chess 1997 Trust, for which he and his spouse serve as sole trustees and sole beneficiaries, as disclosed in the filing. The Form 4 was signed by Kendra Fox as Attorney-in-Fact for Robert Chess and filed on August 11, 2026.

What Was Disclosed

The filing discloses a same-day option exercise and share sale by Twist Bioscience director Robert Chess on August 7, 2026, conducted under a pre-established Rule 10b5-1 plan. After the transactions, Chess directly owns 21,084 shares and indirectly holds 42,528 shares via the Chess 1997 Trust.