$ATRA is one of biggest winner #stocks today. read more:

Atara Biotherapeutics, Inc. (symbol: ATRA) was one of the biggest winners
of the trading day today (2016-04-06), gaining 15.24%. The number of shares
that changed hands was 318,295, or about 1.2 times the average daily volume
in the stock.
The closing price was $22.84, amounting to a market cap of $653,930,000,
about -65.16% off the highest price in the last 12 months. The stock has
been trading at a range between $13.31 and $65.56.
ATRA is in the Biotechnology: Biological Products (No Diagnostic
Substances) industry, part of the Health Care sector. It first went public
in 2014.