$BLUE is one of biggest losers #stocks today. read more:

bluebird bio, Inc. (symbol: BLUE) was one of the worst losers of the
trading day today (2015-12-07), losing -37.54%. The number of shares that
changed hands was 10,062,325, or about 7 times the average daily volume in
the stock.
The closing price was $52.25, amounting to a market cap of $1,920,000,000,
about -73.52% off the highest price in the last 12 months. The stock has
been trading at a range between $45.24 and $197.35.
BLUE is in the Biotechnology: Biological Products (No Diagnostic
Substances) industry, part of the Health Care sector. It first went public
in 2013.