Certain Common Stock of bluebird bio, Inc. are subject to a Lock-Up Agreement Ending on 3-FEB-2024. These Common Stock will be under lockup for 46 days starting from 19-DEC-2023 to 3-FEB-2024.

Details:
The directors and executive officers have agreed with the underwriters that for a period of 45 days after the date of this prospectus supplement, not to dispose of or hedge any of their common stock or securities convertible into or exchangeable for shares of common stock, subject to certain exceptions.