Order types
Order types are the categories of trading instruction sent to a broker.
Common categories include market orders, limit orders, stop orders, and stop-limit orders. Their precise trigger, protection, and execution rules depend on the broker, exchange, and product.
This page covers the mechanic; it is not trading advice.
Order behaviour at a real price
A buy market order on EUR/USD with the ask at 1.0822 fills at the best available price the moment the order reaches the broker — usually 1.0822, but in fast markets it may slip to 1.0823 or worse.
A buy limit at 1.0820 can execute only at 1.0820 or better but may remain unfilled. In a broker-defined plain-stop example, a buy stop at 1.0850 submits a market order when the ask reaches its trigger, so the fill price is not guaranteed. A stop-limit or protected stop follows different venue-defined rules.
What each order type guarantees, and where they differ
The order types make different trade-offs. A market order prioritises execution but does not guarantee a price. A limit order controls the permitted price but may not execute. A stop adds a price condition that activates another instruction; whether that instruction is a market order, limit order, or protected limit order depends on its type and venue.
The gap between a reference price and the actual fill is slippage. Market orders and broker-defined plain stops that submit market orders can experience it; stop-limit and protected-stop instructions have different price-protection and non-fill mechanics.
SlippageWhy the fill price differs from the click price, the three directions it runs, and how to size for it.Each instruction has its own page with the depth this overview leaves out:
Market orderAn instruction that prioritises prompt execution at the best available price rather than control of the fill price.Limit orderA fill only at a set price or better, with the risk of not filling at all.Stop orderA price-triggered instruction whose execution and non-fill risks depend on the venue and stop type.Related terms
Related articles
Common questions
What is slippage?
Slippage is the difference between the price displayed at the moment an order is placed and the price at which it actually fills. Slippage occurs when the market moves between order submission and execution, or when the displayed depth at the requested price is insufficient to fill the entire order. Slippage is asymmetric: market orders during volatility may fill at materially worse prices, while limit orders are never filled at worse prices than specified — they may simply not fill at all.
When is a buy stop order used instead of a buy limit?
A buy stop and a buy limit are different instructions. A buy limit at 1.0820 permits execution at 1.0820 or lower and can remain unfilled. A buy stop uses a price condition above the current market to activate its specified order. A broker-defined plain buy stop may submit a market order; a buy stop-limit submits a limit order and can remain unfilled. Exact trigger and execution rules depend on the venue.