X0508 4 2025-02-10 false 0001293971 bluebird bio, Inc. BLUE 0001839697 Obenshain Andrew C/O BLUEBIRD BIO, INC. 455 GRAND UNION BOULEVARD SOMERVILLE MA 02145 true true false false President and CEO false Common Stock 2025-02-10 4 A false 763.00 0.00 A 19248.00 D Represents shares earned from a performance stock unit (PSU) award granted to the Reporting Person on February 1, 2022, based on certain performance conditions. On February 9, 2025, the Compensation Committee of the Board of Directors determined that certain performance conditions have been satisfied. /s/ Sydney Gaylin, Attorney-in-Fact 2025-02-12