Quick answer
Short selling is generally the sale of a stock you do not own, using shares borrowed for delivery, in the hope of buying them back later at a lower price [1]. If the price rises instead, the loss has no upper limit.
#How does a short sale work?
The four steps of a short sale
Borrow
Your broker lends you shares, usually through a margin account [1].
Sell
You sell the borrowed shares at today's price and receive the cash.
Buy back
Later you buy the same number of shares, ideally at a lower price.
Return
You return the shares to the lender and keep any difference, minus costs.
The SEC's bulletin uses this example: borrow shares at $60 and sell them; if the price falls to $40 you profit $20 a share before fees, but if it rises to $80 you lose $20 a share [1].
Worked example
Short 100 shares at $60
You short 100 shares at $60. Interest, fees and dividends are ignored here.
- Cash from the short sale (100 × $60)
- $6,000
- Price falls to $40: buy back (100 × $40)
- $4,000 → gain $2,000
- Price rises to $80: loss (100 × $20)
- −$2,000
- Price rises to $150: loss (100 × $90)
- −$9,000
- For comparison, the most a buyer of 100 shares at $60 can lose
- $6,000
A buyer's loss stops at what they paid. A short seller's loss keeps growing as long as the price keeps rising.
Hypothetical figures calculated in code.
#Why is short selling riskier than buying?
The SEC puts it directly: a traditional long position risks only the amount invested, while shorting leaves an investor open to the possibility of unlimited losses, since a stock can theoretically keep rising indefinitely [1]. On top of price risk come running costs.
| Item | What happens |
|---|---|
| Interest on the loan | Your brokerage firm charges interest on the borrowed shares |
| Margin rules | You are subject to the margin rules, as when buying on margin |
| Dividends | If the stock pays a dividend, you must pay it to the lender |
Margin calls can force you to add cash or close the position at a bad moment; read margin accounts explained before considering it.
#What is short interest?
Short interest is the total of open short positions in a stock at a point in time. FINRA describes it as a snapshot of open short positions on brokerage firms' books on a given settlement date, reported twice a month, around the middle and at the end of each month [2]. FINRA also notes that investors short to profit from price declines or to hedge other positions [2]. Short interest is not the same as daily short sale volume [2].
#What is naked short selling?
In a naked short sale, the seller does not borrow or arrange to borrow the shares in time to deliver them to the buyer within the standard one-day settlement period, so the trade fails to deliver [1]. The SEC notes this is not necessarily a violation of the securities laws in itself. Regulation SHO was adopted partly to address persistent failures to deliver and potentially abusive "naked" short selling; compliance with it began on January 3, 2005 [1].
Related terms
Frequently asked questions
Is short selling legal?
Yes, when done under the rules, including arranging to borrow the shares. Brokers set their own requirements on top, and not every account is allowed to short.
Can a beginner short a stock?
It usually requires a margin account and approval from the broker. Because losses can exceed the money you put in, it is generally treated as an advanced strategy.
Sources
Grade A = primary source (regulator, government agency, official rulebook or the index provider's own documents). Numbers in brackets in the text point here.
- U.S. SEC — Investor.gov. An Introduction to Short Sales — Investor Bulletin (2026). Accessed 2026-10-03.A
- FINRA. Short Interest (2023). Accessed 2026-10-03.A
This page is general education, not personal financial, tax or legal advice. Figures in worked examples are hypothetical and calculated before taxes and fees unless stated. Rules and limits change; check the linked primary sources for the current version. How we check every page.
