X0609 4 2026-05-26 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 2026-05-26 4 M false 24282 8.82 A 871154 D Common Stock 2026-05-26 4 S false 24282 65.0789 D 846872 D Common Stock 2026-05-27 4 M false 25017 8.82 A 871889 D Common Stock 2026-05-27 4 S false 23752 65.2392 D 848137 D Common Stock 2026-05-27 4 S false 1265 66.2813 D 846872 D Employee Stock Option (right to buy) 5.95 2025-09-28 Common Stock 0 0 D Employee Stock Option (right to buy) 26.66 2028-11-18 Common Stock 0 266539 D Employee Stock Option (right to buy) 23.33 2029-10-23 Common Stock 0 131290 D Employee Stock Option (right to buy) 67.85 2022-12-19 2030-08-31 Common Stock 64950 64950 D Employee Stock Option (right to buy) 8.82 2026-05-26 4 M false 24282 0 A 2027-09-28 Common Stock 24282 116926 D Employee Stock Option (right to buy) 8.82 2026-05-27 4 M false 25017 0 A 2027-09-28 Common Stock 25017 91909 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 May 27, 2025. Represents the weighted average sales price per share. The shares sold at prices ranging from $65.00 to $65.505 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $65.00 to $65.93 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. Represents the weighted average sales price per share. The shares sold at prices ranging from $66.09 to $66.72 per share. Full information regarding the number of shares sold at each price shall be provided upon request to the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer. The option is immediately exercisable. 25% of the shares subject to the option vested on September 1, 2016 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. 20% of the shares subject to the option vested and became exercisable on October 31, 2019 and 1/60th of the shares subject to the option vest and become exercisable on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date. 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. The option is immediately exercisable. 10% of the shares subject to the option vested on September 28, 2017, 15% of the shares subject to the option vested on September 28, 2018, 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. /s/ Kendra Fox, as Attorney-in-Fact for Emily M. Leproust 2026-05-28