Glossary · Defined term
Market order
A market order is an instruction to buy or sell a stock immediately at the best available current price. See how it differs from a limit order.
Last updated Oct 2, 2026
What it means
A market order is an instruction to buy or sell a stock immediately at the best available current price. It prioritizes certainty of execution over certainty of price: the trade will almost always fill, but the exact price is whatever the market offers in that moment. In calm, heavily traded stocks the fill is usually close to the quoted price. In fast-moving or thinly traded stocks, the execution price can differ noticeably from the last quoted price, a phenomenon called slippage. Investors who care more about getting a specific price use limit orders instead.
An example
For illustration, a stock is quoted at $100 and an investor places a market sell order. In normal trading it might fill at $99.99, but if bad news breaks and buyers vanish, the same order could fill at $97 as it sweeps down through the available bids. The order guaranteed a sale, not a price.