By TheStreet Staff What Is a Stop Order? When an investor instructs their broker (usually via a trading application on their phone or computer) to buy or sell a stock on their behalf, they do so with an order. There are three main types of orders—market, limit, and stop. A stop order is unique in that it instructs a broker to buy or sell a stock immediately if it trades at (or past) a specified “stop price.” The stop price is not necessarily the price at which the order will execute, however—the stock reaching the specified stop price is simply what triggers the order to execute. Instead, stop…