Short interest in bluebird bio Inc (NASDAQ:BLUE) increased during the last reporting period, rising from 43.64M to 49.57M. This put 27.62% of the company's publicly available shares short.

Short interest for bluebird bio gives investors a sense of the degree to which investors are betting on the decline of bluebird bio's stock. Short interest data is updated every two weeks.

Based on the recent average volume of 5.51M shares traded per day, it would take 9 day(s) for holders of this short interest to close out their positions without sending the stock sharply higher.