It's actually "limit order." It is a direction to a stockbroker to buy or sell at a specific price, or better. If it is a buy limit order, the broker will buy for you if the stock is at the limit order price or lower, and if it is a sell limit order, the broker will sell for you if the stock is at the limit order price or higher. A buy limit order is similar to a long call, and a sell limit order is similar to a long put.