| SC 13G/A | 2020-02-14 | Capital World Investors | bluebird bio, Inc. | 5,266,990 | 9.5% | EDGAR |
| SC 13G | 2020-02-14 | SANDS CAPITAL MANAGEMENT, LLC | bluebird bio, Inc. | 3,176,644 | 5.7% | EDGAR |
| SC 13G/A | 2020-02-12 | VANGUARD SPECIALIZED FUNDS | bluebird bio, Inc. | 0 | 0.0% | EDGAR |
| SC 13G/A | 2020-02-12 | VANGUARD GROUP INC | bluebird bio, Inc. | 3,771,360 | 6.8% | EDGAR |
| SC 13G/A | 2020-02-07 | FMR LLC | bluebird bio, Inc. | 6,121,442 | 11.1% | EDGAR |
| SC 13G/A | 2020-02-05 | BlackRock Inc. | bluebird bio, Inc. | 2,925,336 | 5.3% | EDGAR |
| SC 13G/A | 2020-01-08 | WELLINGTON MANAGEMENT GROUP LLP | bluebird bio, Inc. | 7,548,613 | 13.6% | EDGAR |
| SC 13G/A | 2019-12-10 | Capital International Investors | bluebird bio, Inc. | 2,197,573 | 3.9% | EDGAR |
| SC 13G/A | 2019-11-08 | Capital World Investors | bluebird bio, Inc. | 5,607,206 | 10.1% | EDGAR |
| SC 13G | 2019-11-05 | BAILLIE GIFFORD & CO | bluebird bio, Inc. | 872,274 | 1.6% | EDGAR |
| SC 13G/A | 2019-02-14 | GROWTH FUND OF AMERICA | bluebird bio, Inc. | 5,195,960 | 9.4% | EDGAR |
| SC 13G/A | 2019-02-14 | PRICE T ROWE ASSOCIATES INC /MD/ | bluebird bio, Inc. | 1,271,545 | 2.3% | EDGAR |
| SC 13G/A | 2019-02-14 | Capital Research Global Investors | bluebird bio, Inc. | 6,699,431 | 12.2% | EDGAR |
| SC 13G | 2019-02-14 | Capital World Investors | bluebird bio, Inc. | 3,713,572 | 6.7% | EDGAR |
| SC 13G/A | 2019-02-13 | FMR LLC | bluebird bio, Inc. | 8,204,161 | 15.0% | EDGAR |
| SC 13G/A | 2019-02-12 | WELLINGTON MANAGEMENT GROUP LLP | bluebird bio, Inc. | 7,586,427 | 13.9% | EDGAR |
| SC 13G/A | 2019-02-11 | VANGUARD GROUP INC | bluebird bio, Inc. | 4,796,557 | 8.8% | EDGAR |
| SC 13G/A | 2019-02-04 | BlackRock Inc. | bluebird bio, Inc. | 2,986,142 | 5.5% | EDGAR |
| SC 13G | 2019-01-31 | VANGUARD SPECIALIZED FUNDS | bluebird bio, Inc. | 2,815,599 | 5.1% | EDGAR |
| SC 13G/A | 2019-01-24 | BAILLIE GIFFORD & CO | bluebird bio, Inc. | 4,529,123 | 8.3% | EDGAR |