A quote that shows both the price at which the dealer will buy and the price at which they will sell, without asking which way you intend to trade.
Market convention in wholesale forex is that a dealer asked for a price in a given size must show both sides. It stops the customer's intention from leaking before they deal, and it is one of the reasons interbank spreads stay tight.
Retail platforms show a two-way price permanently on the chart, but the same idea applies: the bid is what you receive when selling and the ask is what you pay when buying. The difference between them is your entry cost before any commission.
Example: a bank shows 40 / 43 in EUR/USD in 20 million. The customer can sell at 1.0840 or buy at 1.0843. On 20 million, the three-pipette spread is worth about $600.
Original diagrams for the ideas on this page. Illustrative, not real market data.
The bid-ask spread. Buy orders sit below, sell orders above, and the gap between the best bid (50.01) and best ask (50.04) is the spread you pay to cross. Bar length shows the size resting at each price.
Educational only, not advice. Spotted an error? Post in Site Feedback.