Prothena Co. plc (NASDAQ:PRTA – Get Free Report) was the recipient of a large decline in short interest in January. As of January 31st, there was short interest totalling 5,750,000 shares, a decline of 8.1% from the January 15th total of 6,260,000 shares. Based on an average trading volume of 845,900 shares, the short-interest ratio […]