Short selling could very well be the reason for 30% declinefdfd, however 2.5M is a lot! If you compare the CXRX share price with the short interest on NASDAQ between Spetember 2015 and January 2016 it looks like an inverse and logical correlation between the October 21 LOW and the December 28 HIGH. That is, there was only a 1 day short interest when CXRX was trading near $25 (not much expecteation that the SP would go lower), and the relatively high 5-6 day short interest in late December when CXR was trading near CDN $58.