A stop-loss is an order that tells your broker to sell a security once it falls to a price you choose, so a position cannot keep bleeding while you are not watching. Set a stop below your purchase price and, in theory, the trade closes before the loss grows. It is a risk-management tool, not a profit tool, and it comes with real catches: the price you get is not guaranteed. This is general information, not personalized investment advice; verify any strategy against your own situation.
How a stop-loss works
You attach a stop price to a holding. When the market trades at or through that level, the order activates. A plain stop-loss then turns into a market order, meaning it sells at the next available price. In a calm market that price is close to your stop; in a fast or thin market it can be noticeably worse.
That gap between your intended stop and the actual fill is called slippage, and it is the single most misunderstood part of using stops.
Stop-loss vs stop-limit vs trailing stop
| Order type |
What triggers it |
What you get |
| Stop-loss (market) |
Price hits the stop |
Sells at next price, fill likely but price not guaranteed |
| Stop-limit |
Price hits the stop |
Sells only at your limit or better, may not fill |
| Trailing stop |
Price falls a set distance from its peak |
Stop follows the price up, locks in gains |
A stop-limit protects you from a terrible fill but risks not executing at all if the price blows past your limit. A trailing stop is useful for letting a winner run while still defining your exit.
When it helps and when it does not
Stops shine when you cannot babysit a position and want a defined maximum loss. They also impose discipline, removing the temptation to hope a falling stock recovers.
They struggle with overnight gaps, where a stock opens far below your stop and sells you out at a bad price, and with normal volatility, where a too-tight stop triggers on routine noise. For long-term, diversified investors, frequent stop orders can do more harm than good. If you are early in your journey, start with the basics in how to buy stocks.
What to skip
- Stops that are too tight. Ordinary daily swings will trigger them and lock in unnecessary losses.
- Assuming the fill equals the stop. A plain stop sells at the next price, which can be worse in a fast market.
- Using stops on illiquid securities. Thin trading widens slippage dramatically.
- Treating stops as a substitute for position sizing. How much you buy matters more than where you set the exit.
FAQ
Does a stop-loss guarantee my exit price?
No. A plain stop becomes a market order and fills at the next available price, which can differ from your stop, especially in volatile conditions.
What is the difference between a stop and a limit order?
A limit order sets the price you are willing to accept; a stop order sets the trigger that activates a sale. A stop-limit combines both.
Should long-term investors use stop-losses?
Often not. Frequent stops can shake you out of solid holdings on noise. They suit active traders more than buy-and-hold investors.
What is a trailing stop?
A stop that moves up as the price rises, staying a set distance below the peak, so it locks in gains while still defining a downside exit.
Where to go next
Read a beginner guide to buying stocks, learn what day trading really involves, and understand short selling.