The action in bluebird bio (BLUE) over the last month has been manic to say the least. At first the trading was positive, as the stock rallied to a three-month high in mid-June on the back of impressive results from a Phase I/II study of a drug that treats a blood disease called beta-thalassemia. But by the end of the month BLUE had given back those gains and then some. One of the biggest culprits was Global Blood Therapeutics’ (GBT) announcement that it had received positive data from a Phase III drug trial of a treatment for sickle cell anemia. This blood disease has been a large focus of many biotechs in recent years.