Ask An ask, also called an offer, is an order to sell a stated quantity at a stated price or better. The lowest ask is the best offer. Also known as offer. market microstructure · updated 2026-09-23 See also Bid — A bid is an order to buy a stated quantity at a stated price or better. The highest bid in the book is the best bid, and it is one… Bid-ask spread — The bid-ask spread is the difference between the best bid and the best ask. It is the immediate cost of trading in and straight ba… Terms that refer here Bid · Order book Back to the full glossary — 261 defined terms.