Ask
Ask is the lowest price a seller is currently willing to accept. It is the best available sell quote in an order book.
Definition
Ask is the lowest price currently offered by sellers in the order book. The best ask is the top sell quote you can buy from immediately.
Why it matters
Ask is the other side of the bid ask spread. Along with the bid, it defines the midquote, which is used to compute effective spread.
How to use it
• If you place a market buy, you will typically execute at the best ask (or worse if depth is thin).
• If you place a limit sell, your order sits on the ask side at your chosen price.
Common pitfalls
Stale quotes: In fast markets, the ask can change between click and fill.
Thin depth: The best ask might have very little size. Larger orders can sweep multiple levels.