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

Merrimack Pharmaceuticals, Inc. (symbol: MACK) was one of the biggest
winners of the trading day today (2016-10-21), gaining 8.2%. The number of
shares that changed hands was 8,134,553, or about 2.9 times the average
daily volume in the stock.
The closing price was $5.54, amounting to a market cap of $715,990,000,
about -45.58% off the highest price in the last 12 months. The stock has
been trading at a range between $4.39 and $10.18.
MACK is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2012.