Mid-Price

The mid-price is the midpoint between the bid and the ask: add the two and halve the result. Nobody trades at it — you buy at the ask and sell at the bid — but it is the standard way of describing where a market is without taking a side, and most charts, index calculations and valuation feeds are built from it. Its main practical use is as a cost benchmark. The distance from the mid to the price you actually dealt at is half the spread if you traded at the quote, more if you were slipped, less if you were improved, and expressing that gap in the account currency is how transaction cost analysis turns execution into a number. It also explains why a position shows a small loss the instant it is opened when the platform values it at the mid or the closing side: no money has been lost, the spread has simply been recognised straight away.