A Stop Order is a type of trading order used in financial markets to buy or sell a security once it reaches a specified price, known as the stop price. This order helps investors limit potential losses or lock in profits by automatically executing a trade when the market price hits the predetermined level. There are two main types of stop orders: a Stop-Loss Order, which sells a security to prevent further losses, and a Stop-Buy Order, which buys a security to capitalize on upward price movement. Both types are essential tools for managing risk in trading strategies involving stocks, options, or other financial instruments.