X0306 4 2022-02-01 false 0001293971 bluebird bio, Inc. BLUE 0001839697 Obenshain Andrew C/O BLUEBIRD BIO, INC. 60 BINNEY STREET CAMBRIDGE MA 02142 true true false false President and CEO Common Stock 2022-02-01 4 A false 18000.00 0.00 A 268936.00 D Stock Option (right to buy) 7.80 2022-02-01 4 A false 90000.00 0.00 A 2032-02-01 Common Stock 90000.00 90000.00 D Restricted stock unit awards vest over a four-year period at the rate of 25% on 01/04/2023, 25% on 01/04/2024, 25% on 01/04/2025, and 25% on 01/04/2026. Reflects a correction to the balance of securities beneficially owned to increase the balance by 4,240 shares, with respect to shares incorrectly reported as sold to satisfy tax withholding obligations of the reporting person in connection with the vesting of Restricted Stock Units. This stock option vests over a four-year period at the rate of 25% on 01/04/2023 and then in 36 equal monthly installments thereafter. /s/ Helen C. Fu, Attorney-in-Fact 2022-02-03