Sun Life Financial Inc. (NYSE:SLF - Get Free Report) (TSE:SLF) was the recipient of a large increase in short interest in the month of July. As of July 31st, there was short interest totaling 5,095,872 shares, an increase of 84.8% from the July 15th total of 2,757,571 shares. Approximately 0.9% of the company's shares are sold short. Based on an average daily volume of 581,283 shares, the days-to-cover ratio is currently 8.8 days.