Short Interest

Short interest is the total number of a company's shares currently sold short and not yet bought back. It is usually quoted as a percentage of the float: 40 million shares short against a 100 million share float is 40% short interest.

The data comes from FINRA, which collects short positions from brokers twice a month (mid-month and month-end settlement dates) and publishes the totals several days later. That lag matters — the number you see can be up to two weeks stale, and a squeeze can rewrite it before the next print.

High short interest cuts two ways. It signals that sophisticated money expects the stock to fall, and it also builds the fuel for a squeeze: every short is a forced future buyer if the price runs against them. Readings above 20% of float put a stock on most squeeze scanners.