In plain English
What Execution price means
If you send an order, the execution price is the price you really get, not necessarily the price you saw on screen. For market orders it may vary from the last quoted bid or ask; for limit orders it should be at the limit price or better, if filled. The difference matters because it determines the trade’s immediate cost or proceeds.
Why it matters
Execution price is the core input for calculating spread cost, slippage, realized profit and loss, and whether an order outcome matched expectations. In regulated markets, firms are also assessed on how well they execute relative to available prices and trading conditions.
Example
A trader sends a market buy order for EUR/USD when the ask is 1.0850. The order fills at 1.0852 because price moved before the order reached liquidity. The execution price is 1.0852, so the trader paid 0.0002 more than the quote they initially saw. This simplified example ignores commission.
Quick answers
Common questions
Is execution price always the best available price?+
No. It is the actual fill price, which can be worse or better than the quote you expected.
Does a limit order guarantee the execution price?+
It can control the worst acceptable price, but it does not guarantee a fill.
Sources