X0609 4 2026-10-01 0001581280 Twist Bioscience Corp TWST 0001753655 Leproust Emily M. false C/O TWIST BIOSCIENCE CORPORATION 681 GATEWAY BLVD. SOUTH SAN FRANCISCO CA 94080 true true false false Chief Executive Officer 1 Common Stock 2026-10-01 4 S false 655 200 D 613044 D Common Stock 2026-10-02 4 S false 45736 188.884 D 567308 D Employee Stock Option (right to buy) 23.33 2029-10-23 Common Stock 131290 131290 D Employee Stock Option (right to buy) 67.85 2022-12-19 2030-08-31 Common Stock 64950 64950 D The transactions reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 15, 2026. Represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of Restricted Stock Units. These sales are mandated by the Issuer's election under its equity incentive plans to require the satisfaction of a tax withholding obligation to be funded by a "sell to cover" transaction and do not represent discretionary trades by the Reporting Person. 25% of the shares subject to the option vested on October 24, 2020, and 1/48th of the shares subject to the option vest on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date. Represents performance stock options granted to the reporting person on September 1, 2020, that vested and became exercisable on December 19, 2022 as a result of the reporting person having met the applicable performance criteria. /s/ Kendra Fox, as Attorney-in-Fact for Emily M. Leproust 2026-10-05