 Pioneer Natural Resources NYSE:PXD was the target of a large decrease in short interest in June. As of June 15th, there was short interest totalling 5,640,000 shares, a decrease of 6.2 from the May 31st total of 6,010,000 shares. Based on an average daily volume of 3,180,000 shares, the days-to-cover ratio is currently 1.8 days. ... 