Short Interest
The total number of shares sold short and not yet repurchased to close the position.
What is Short Interest?
Short interest is the total quantity of a company's shares that have been sold short but not yet bought back (covered). It is expressed as a share count, a percentage of shares outstanding (short interest ratio), and a "days to cover" figure — how many days of average trading volume would be needed to close all short positions. High short interest reflects widespread bearish sentiment. It can also create a short squeeze: when the price rises sharply, short sellers rush to cover losses by buying shares, further accelerating the price increase. In the U.S., FINRA and exchanges report aggregate short interest data twice monthly. Short interest can also serve as a contrarian signal — extremely high short interest sometimes precedes strong rallies.
Example
GameStop in January 2021 had short interest exceeding 100% of its float — meaning more shares were sold short than were freely tradable. When retail investors coordinated to buy the stock, short sellers faced mounting losses and began covering, which drove the price from around $20 to nearly $500 within days. The extreme short interest was both the cause and the fuel of the historic short squeeze.
Source: FINRA — Short Interest Reporting