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

Merrimack Pharmaceuticals, Inc. (symbol: MACK) was one of the worst losers
of the trading day today (2016-01-11), losing -11.55%. The number of shares
that changed hands was 2,421,235, or about 2 times the average daily volume
in the stock.
The closing price was $5.82, amounting to a market cap of $672,640,000,
about -57.95% off the highest price in the last 12 months. The stock has
been trading at a range between $5.79 and $13.84.
MACK is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2012.