Simple definition
Short selling means borrowing shares you don't own, selling them now, and hoping to rebuy them cheaper later to return them — pocketing the difference if the price falls. Think of it as selling something borrowed and betting you can replace it for less. If the price rises instead, your losses can grow without limit.
Why it matters
Short selling is one of the riskiest strategies an investor can use, and most people never need it. When you buy a stock, the most you can lose is what you paid. When you short, losses are theoretically unlimited, because a stock's price can keep climbing with no ceiling while you owe the shares back.
Real-life example
Suppose you short a stock at $50, expecting it to fall. Instead it rises to $80. To close the position you must buy it back at $80, losing $30 a share — and it could have gone higher still. These are rounded, hypothetical figures to show the risk, not advice to try it.
Common mistakes
- Underestimating that losses on a short have no ceiling, since a price can keep rising indefinitely.
- Treating short selling as a normal way to invest rather than a high-risk, advanced strategy.
- Forgetting you're borrowing shares and can be forced to buy them back at a bad time.
- Ignoring the fees, interest, and margin requirements that come with holding a short position.
Pro tips
- Understand deeply that short-selling losses are theoretically unlimited before ever considering it.
- Recognize that most long-term investors build wealth without ever selling short.
- Know that a rising price can force you to buy back at a large loss on someone else's schedule.
- Learn the full mechanics and costs, including borrowing and margin, before risking any money.
Related Money Dictionary terms
- Margin AccountA brokerage account that lets you borrow money to invest, which can boost gains but also magnify losses.
- LeverageUsing borrowed money to increase the size of an investment, raising both potential returns and potential losses.
- VolatilityHow sharply and often an investment's price swings up and down over a given period.
- OptionsContracts that give you the right, but not the obligation, to buy or sell an investment at a set price by a deadline.
- Margin CallA demand from your broker to add money or sell holdings when borrowed-investment losses grow too large.
- StockA share of ownership in a company that you can buy and sell, giving you a small stake in its profits and growth.
Frequently asked questions
Why are short-selling losses called unlimited?
When you buy a stock, its price can only fall to zero, so your loss is capped at what you paid. When you short, you profit if the price falls but lose if it rises — and there's no ceiling on how high a price can go. That's why the potential loss is described as unlimited.
How does short selling actually work?
You borrow shares through your broker, sell them at today's price, and later buy them back to return to the lender. If the price fell in between, you keep the difference; if it rose, you take the loss. It requires a margin account, and borrowing costs and forced buy-backs make it risky and advanced.
Is short selling something a regular investor should do?
For most people, no. Short selling carries unlimited loss potential, ongoing borrowing costs, and the risk of being forced to close at the worst moment. It's an advanced strategy used by experienced traders, and the vast majority of long-term investors reach their goals without ever shorting a single share.
Knowing what Short Selling means is knowledge — the first half. A brick gets placed when you act on it: Before ever considering short selling, read investor.gov's and FINRA's warnings on its unlimited-loss risk — for most investors, the right step is to skip it..
Sources & references
More in Investing
Plain-English education — not personalized legal, tax, or investment advice.