In trading, the term buy order is used in reference to any order by which an investor instructs a broker to buy assets on their behalf.
There are many different instructions which can be added to buy orders in order to accomplish specific tasks. The most common buy orders are buy market orders (the broker buys assets at the best available offer), buy stop orders (the broker only buys assets if their value reaches a predetermined price) and buy limit orders (the broker only buys assets if they can purchase them at a predetermined price or better).
An order which instructs a broker to sell assets on behalf of an investor is known as a sell order.
Buy orders may be placed by investors to brokers using Internet-based trading platforms, over the phone, in person, or by electronic or postal mail.