BID, ASK, AND SIZE When you enter an order to buy or sell a stock, you see the bid and ask for a stock and some other numbers. What are the bid and ask, and what do those numbers mean? One, the bid, is what you need to know when you are selling a stock. The other, the ask (or offer) is what you need to know when you're buying. Closing Price vs. Asking Price - Budgeting Money Oct 10, 2018 · The difference between the lowest ask price and the highest bid price for a stock is known as the bid-ask spread. Stocks or other securities with a smaller bid-ask spread are considered more liquid since there will be more successfully completed trades for these securities.