Amphastar Pharmaceuticals, Inc. (NASDAQ:AMPH – Get Rating) was the target of a large drop in short interest in the month of March. As of March 31st, there was short interest totalling 1,310,000 shares, a drop of 10.3% from the March 15th total of 1,460,000 shares. Based on an average trading volume of 286,100 shares, the […]