Ask is the price at which a seller is willing to sell an asset. In an order book, ask refers to the sell side of the market.

Best ask is the lowest available price among active sell orders. For example, if sellers offer an asset at $60,100, $60,050, and $60,000, the best ask is $60,000.

Ask and bid

The opposite side consists of bid orders from buyers. The difference between the best ask and best bid forms the spread.

A market buy order generally executes against available ask orders. If the buy order is larger than the quantity available at the best ask, it can continue through additional price levels.