Sun Life Financial Inc. (NYSE:SLF - Get Free Report) (TSE:SLF) saw a significant drop in short interest in September. As of September 15th, there was short interest totaling 3,935,950 shares, a drop of 36.4% from the August 31st total of 6,188,802 shares. Based on an average daily trading volume, of 684,978 shares, the short-interest ratio is presently 5.7 days. Approximately 0.7% of the shares of the stock are short sold.