$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 (2016-09-22), gaining 20.87%. The number
of shares that changed hands was 13,469,722, or about 7.0 times the average
daily volume in the stock.
The closing price was $6.14, amounting to a market cap of $793,530,000,
about -43.41% off the highest price in the last 12 months. The stock has
been trading at a range between $4.39 and $10.85.
MACK is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2012.