In the military, stop-loss means that a person cannot separate from the military. They would like to retire or leave the military but are not allowed because a stop-loss order has been issued. In the stock market, it can be used to sell a stock. The stock is listed at $25 and you have a stop-loss order in at $20. When the share hits $20, you are not willing to lose more than $5, and have entered a stop-loss order with your broker. To prevent you from losing anymore than $5, the broker is required to sell your stock at $20. A stop-loss order limits the losses.