An order to buy a stock at or below a specified price, or to sell a stock at or above a specified price. For instance, you could tell a broker "buy me 100 shares of XYZ Corp at $8 or less" or "sell 100 shares of XYZ at $10 or better" The customer specifies a price, and the order can be executed only if the market reaches or betters that price. A conditional trading order designed to avoid the danger of adverse unexpected price changes.