Days to cover, also known as the short interest ratio, is calculated by taking a stock's total number of shares sold short and dividing that number by the stock's average daily trading volume. For example, if a stock has 1 million shares sold short and its average daily trading volume is 100,000 shares, then the days to cover would be 10 days. That is, it would take 10 days for short sellers to cover their entire short position based on the average daily volume of shares traded. In general, the higher a stock's days-to-cover figure, the more susceptible it may be to a short squeeze. If days to cover for stock A and stock B are two days and 20 days respectively, then stock B may be more vulnerable as a short squeeze target.