 Amphastar Pharmaceuticals Inc NASDAQ:AMPH was the target of a significant decrease in short interest in the month of July. As of July 15th, there was short interest totalling 2,630,000 shares, a decrease of 6.7 from the June 30th total of 2,820,000 shares. Based on an average trading volume of 347,100 shares, the days-to-cover ratio is ... 