Market order

A market order is the simplest trade instruction: "buy now" or "sell now". A buy market order fills at the current ask price; a sell fills at the current bid. You choose the size, not the price.

Because the price can change between the moment you click and the moment the broker processes the order, the fill can differ from the price on your screen. That difference is slippage. It can be positive or negative, and it is usually tiny in liquid pairs during busy hours and larger around news releases, at the daily rollover or when markets reopen after a weekend.

Example

Illustrative figures: EUR/USD shows 1.08500 bid and 1.08510 ask. You send a market order to buy 1 standard lot. In a calm market you are likely to be filled at 1.08510. If a data release hits at that instant and the ask jumps to 1.08540, you may be filled there instead: 3 pips of negative slippage, or 30 dollars on a standard lot, since each pip is worth about 10 dollars.

Execution modes

On MetaTrader you may see "market execution" or "instant execution". With market execution, the order fills at whatever price is available. With instant execution, the broker tries to fill at your requested price and, if the price has moved beyond your allowed deviation, may return a requote instead.

Practical note

If the exact entry price matters more than getting in, a limit order is the alternative: it fills only at your price or better, but may not fill at all. Our guide to order types compares them, and slippage explained covers execution in fast markets.