Bid

The bid is the highest price a buyer is willing to pay for a crypto asset in an order book at a given time. It is the buy-side price available to sellers at a specific moment. The bid is usually compared with the ask, which is the lowest price a seller is willing to accept. The difference between the bid and ask is called the spread. When a user places a market sell order, the order typically fills against available bids, starting with the highest bid price and moving lower if additional liquidity is needed.

For example, if the highest buyer on an Ethereum order book is willing to pay $4,000, then $4,000 is the bid price for that market at that exact moment in time.