A stop-loss order is a type of order placed by a trader with a broker to sell a security (e.g. forex currency pair, stock, commodity) once it reaches a certain price level. The main purpose of a stop-loss order is to limit potential losses in a trade. If the price of the security falls to the pre-determined level set by the trader, the stop-loss order is triggered, and the security is automatically sold at the current market price, in order to prevent further losses. Stop-loss orders are commonly used in forex trading to manage risk, as well as in other financial markets.