A stop-loss order is your automatic safety net: it sells a stock the moment it drops to a price you set, capping your loss so a small mistake can't turn into a portfolio-wrecking one.
A stop-loss order is an instruction to sell a stock automatically if its price falls to a level you choose (the stop price). Buy at $100 and set a stop at $90, and if the stock drops to $90 your shares are sold — limiting your loss to roughly 10% instead of riding it all the way down.
When the stop price is hit, the stop-loss usually becomes a market order and sells at the next available price. A stop-limit instead becomes a limit order — it won't sell below a floor you set, which protects against a terrible fill but risks not selling at all in a fast drop.
A trailing stop follows the price up. Set a 10% trailing stop and as the stock climbs, the stop price rises with it, always 10% below the peak — so you protect profits while letting a winner run, and you're sold only after a 10% pullback from the high.
Stop-losses enforce risk discipline by removing emotion: the decision to cut a loser is made before you're attached to the position. The catch is that normal volatility or a brief spike can stop you out just before the stock recovers, so the stop's distance must suit the stock's swings.
Practice cutting losses: protecting capital is the hardest habit to learn. Set targets and exits with play money in the day trading simulator and the stock market simulator.
Not advice: educational content only. For authoritative basics see the SEC at investor.gov.
Related: what is a limit order, risk vs reward, and common investing mistakes.
A stop-loss order automatically sells a stock if it falls to a price you set, capping your loss. Buy at $100 with a stop at $90 and you sell near $90 if the stock drops, instead of riding it lower.
A stop-loss becomes a market order when triggered and sells at the next price. A stop-limit becomes a limit order with a price floor, protecting against a bad fill but risking not selling at all.
A trailing stop follows the price upward, staying a set percentage or amount below the peak. It locks in gains by selling only after the stock pulls back from its high.
Yes. Normal volatility or a brief price spike can hit your stop just before the stock recovers, so the stop distance should match how much the stock typically swings.