Trading term

What is Short interest?

Short interest is the number of a company's shares currently sold short, usually quoted as a percentage of the public float. It can exceed 100%, because a borrowed share, once sold, can be borrowed again by its new owner's broker and shorted a second time.

Short interest counts every share that's been sold short and not yet bought back — the open short positions in a stock at a point in time. It's usually expressed as a percentage of the float (the shares actually available to trade), so a stock with 10 million shares short against a 50-million-share float has 20% short interest. A higher number means more traders are positioned for the price to fall, and it's a figure exchanges and data providers publish regularly.

The part that surprises people is that short interest can run past 100% of the float. A short seller borrows a share and sells it to a buyer; that buyer now owns it, often in a margin account, and their broker can lend the same share out again to the next short seller. One physical share can end up supporting two — or more — short positions at once, so the reported short interest can add up to more than the number of shares that exist. Short interest that's large relative to the float is often called a crowded short.

For example

GameStop's short interest reached roughly 140% of its public float on 22 January 2021 — more shares were reported short than the company had available to trade. That's possible because the same shares kept changing hands and getting lent out again, not because more shares existed than were issued.

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Why it matters to you

Short interest is a read on how many traders are positioned against a stock, and a crowded short is a fragile place to stand — a rising price can force a lot of those positions to buy back around the same time. It doesn't tell you whether that will happen or when, only how many people would need to buy if it did.

⚠ High short interest alone doesn't mean a squeeze is coming

It's tempting to read a large short-interest number as a countdown to a short squeeze, but a crowded short can stay crowded for a long time, or unwind quietly as the price drifts down and shorts take profits calmly. Short interest measures how many people are exposed, not whether or when a squeeze fires.

Frequently asked questions

What does short interest mean?

It's the total number of a stock's shares currently sold short and not yet bought back, usually quoted as a percentage of the float. A higher percentage means more traders are betting the price will fall.

How can short interest be over 100%?

Because a share can be lent more than once. A short seller borrows a share and sells it to a new owner, whose broker can then lend that same share out again to another short seller. The same share ends up supporting more than one short position, so the total reported can exceed the float.

Where can I find a stock's short interest?

Exchanges and financial data providers publish it on a regular schedule — in the US, FINRA-member firms report it roughly twice a month. Most brokers and financial data sites show it as a raw share count and as a percentage of the float.

Does high short interest mean a stock will squeeze?

Not by itself. High short interest means a lot of traders would need to buy back if the price rose sharply, which is what makes a squeeze possible — but plenty of heavily shorted stocks never squeeze and just keep falling.

Read the full guide

DerivativesWhat Is Short Selling? How to Bet on a Stock FallingShort selling means borrowing shares, selling them, and buying them back cheaper. How the borrow works, what it costs, and why the loss has no ceiling.14 min read

Related terms

BackwardationBackwardation is when futures prices are lower for later delivery dates — the futures curve slopes downward. It often signals tight near-term supply or strong demand for immediate delivery. For futures holders it creates a positive 'roll yield,' as they sell pricier near-term contracts and buy cheaper later ones.BasisBasis is the difference between an asset's futures price and its current spot (cash) price. It reflects carrying costs, supply and demand, and time to expiry — and it converges to zero as the contract nears expiration, since a future about to settle must match the spot price. Traders watch basis to gauge conditions and to hedge.Borrow feeThe borrow fee is what a short seller pays to rent the shares they've borrowed, quoted as an annual rate on the value of the position and charged for every day the short is held. An easy-to-borrow stock might cost a fraction of a percent a year; a hard-to-borrow one can cost many times that.CFD (contract for difference)A CFD (contract for difference) is a derivative where you and a broker agree to exchange the difference in an asset's price between opening and closing the trade. You never own the underlying — you simply profit or lose on the price move, with leverage. CFDs cover stocks, indexes, commodities and crypto, and are popular outside the US, where they're banned.
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