The amount of shares of stock that have been sold short and have not yet been delivered (i.e., repurchased to close out short positions). High short interest levels indicate that many sellers have sold short, expecting a bearish trend. Many traders, however, view a high short interest level as a insightful indicator of an eminent rise in the short price, because the future stock demand from short sellers seeking to close out their positions will drive the share price up. The lower the short interest, the less traders are expecting an upturn. Therefore, a low short interest position is viewed as a bearish sign by many market watchers.

The short interest figure is published monthly in newspapers (for shares listed on exchanges like NASDAQ, NYSE, AMEX, etc) and indicates how many investors believe stock prices are about to move down.