Two accounts at the same broker can behave differently at the moment of entry. On one, an order at a moving price comes back as a requote and waits for you to accept. On the other, the same order fills immediately at whatever the market offers. Neither is malfunctioning. They are running different execution models, and the choice between them is usually made — silently — when the account is opened.
The distinction in one line each
- Instant execution: you trade at the displayed price or not at all; deviation produces a requote.
- Market execution: your order fills at the best available price, which may differ from the displayed one.
- Instant execution trades certainty of price for uncertainty of fill.
- Market execution trades certainty of fill for uncertainty of price.
Instant execution and the requote
Under instant execution, the price you see on the platform is the price the order is sent at. If the market has moved by the time the order reaches the server, the broker cannot fill at the requested price and returns a requote: a new price, offered for a few seconds, which you accept or decline.
The model gives you a firm price or nothing. That is genuinely valuable when precision matters more than participation — placing a position at a specific level, for instance, where being filled ten pips away defeats the purpose of the entry.
Its cost appears in fast markets. When prices are moving quickly, the probability that any given order arrives at a stale price rises, and requotes multiply. A trader trying to enter during a news release can find themselves clicking through several requotes while the move they wanted to catch runs away. The protection against a bad price becomes a barrier to any price.
Deviation settings soften the trade-off
Most platforms allow a maximum deviation to be set on an instant-execution order — a tolerance in points within which the order fills without asking. Setting it to a few points removes the majority of requotes while still refusing genuinely bad prices. It is the single most useful setting on the order ticket and the least used.
Market execution and slippage
Under market execution the platform's price is indicative. The order is sent without a price condition and filled against whatever liquidity is available when it arrives. There is no requote, because there is no price to reject; there is slippage instead, which can be negative or positive.
In calm conditions on a liquid instrument, the difference from the displayed price is negligible. In fast conditions the fill can be some distance away, and the trader has no opportunity to decline it. The model buys participation and pays for it in price uncertainty.
Crucially, market execution does not mean the order reached an exchange or an external venue. It describes how the price condition is handled, not where the order went. A broker that internalises every order can offer market execution, and many do.
What each model does to your stop-loss
A stop-loss is an instruction to send a market order when a price is touched, and it is therefore subject to whatever execution model the account runs. Under market execution, a stop triggered in a gap fills at the first available price, which may be well beyond the level you set. Under instant execution, brokers do not requote a triggered stop — that would leave the position open in a falling market — so in practice stops behave the same way under both models.
This is worth stating plainly because it disappoints a common assumption. Choosing instant execution does not guarantee your stop-loss price. Only a guaranteed stop, which is a separate product with its own charge, does that.
How to tell which one your account uses
The platform's order ticket is the fastest indicator. If it offers a maximum deviation field, the account is on instant execution. If the ticket shows no price at all beyond the current quote and simply asks for volume, it is market execution. The contract specifications for each instrument state it explicitly, and the same broker may apply different models to different instrument classes — instant on forex, market on indices, for example.
Checking your own execution model
- Open a new order ticket on the instrument you trade most.
- Look for a deviation or maximum slippage field; its presence indicates instant execution.
- Open the instrument's contract specification in the platform and read the execution line.
- Place one minimum-size trade in a quiet hour and compare the fill against the displayed price.
- Repeat once during a busy hour and compare again.
- If the two fills differ in character — one exact, one slipped — you have your answer.
Which to prefer
For most discretionary traders on liquid instruments, market execution with a sensible deviation policy is the practical default: it fills, it is predictable in calm conditions, and it does not interrupt with dialogue boxes. For automated strategies the answer depends entirely on the strategy's tolerance. A system that assumes it always gets filled will misbehave under instant execution; a system that depends on an exact entry price will misbehave under market execution.
The important step is not choosing correctly but knowing which one you have, because the two models fail in opposite ways and the failure only shows up when conditions are difficult.
Common questions
Is market execution better than instant execution?
Neither is better in general. Market execution suits traders who need to be filled; instant execution suits traders who need a specific price. The failure modes are opposite, so the right choice follows from the strategy.
Does market execution mean my order goes to an exchange?
No. It describes how the price condition on the order is handled, not the routing. A broker that fills every order internally can still offer market execution.
Why am I getting requotes only during news?
Because that is when prices move fastest between your click and the server. Under instant execution, an order arriving at a stale price must be requoted. Increasing the deviation tolerance on the order ticket reduces this.
Will instant execution protect my stop-loss price?
No. A triggered stop becomes a market order under both models, so it fills at the best available price. Only a guaranteed stop-loss, offered separately and usually for a fee, fixes the exit price.
