Merrimack Pharmaceuticals (NASDAQ:MACK – Free Report) was downgraded by StockNews.com from a “hold” rating to a “sell” rating in a report released on Friday. Merrimack Pharmaceuticals Price Performance Shares of MACK stock traded down $0.08 during trading hours on Friday, reaching $11.80. 209,960 shares of the stock were exchanged, compared to its average volume of […]