Crypto glossary
Market order
A market order is an instruction to buy or sell an asset immediately at the best available price, trading certainty of execution for certainty of price.
A market order does not name a price. It tells the exchange to fill the requested amount at once against the best orders waiting in the order book: a buy takes the lowest asks and a sell hits the highest bids. If the first price level is not large enough, the order keeps filling at progressively worse prices.
Because it removes liquidity from the book, a market order pays the taker fee, usually higher than the maker fee. Traders use market orders when speed matters more than a small price difference, for example to exit a position during a sharp move. A swap on a DEX works in a similar way, with the slippage tolerance setting as the safeguard.
The main risk is slippage. In thin markets, during news or on small tokens, the average fill price can end up far from the last quoted price. Splitting a large order, checking book depth first or using a limit order reduces that risk.
Example
A trader sends a market sell order for 10 SOL; the first 4 fill at 150.00 dollars and the remaining 6 at 149.90, for an average price of 149.94.
