Understanding Trading, Customer Accounts and Prohibited Activities

An order to buy or sell immediately at the best available price. It guarantees execution but not price.

Execution. It fills at the best price available at that moment, which may differ from the last quote the customer saw.

With little liquidity quoted, the order may fill at a price far from the last trade because it executes against whatever shares are available.

An order to buy or sell at a specified price or better. It guarantees price (if it executes) but not execution.

At or below the current market price. It executes only at the limit price or lower.

At or above the current market price. It executes only at the limit price or higher.