Mast Therapeutics (NYSE:MSTX) was the recipient of a significant decrease in short interest during the month of December. As of December 15th, there was short interest totalling 4,843,237 shares, a decrease of 2.1% from the November 28th total of 4,945,028 shares, Stock Ratings News reports. Mast Therapeutics, Inc. (NYSEMKT:MSTX) belongs to Healthcare sector. Its weekly performance is 16.02%. On last trading day company shares ended … Continue reading Big Moves in Focus: Mast Therapeutics, Inc. (NYSEMKT:MSTX), American Realty Capital Properties, Inc. (NASDAQ:ARCP), Broadridge Financial Solutions (NYSE:BR), KLIC, Republic Bancorp (NASDAQ:RBCAA)