Bid and Ask Definition, How Prices Are Determined, and Example

What Is Bid and Ask?

The term "bid and ask" (also known as "bid and offer") refers to a two-way price quotation that indicates the best potential price at which a security can be sold and bought at a given point in time. The bid price represents the maximum price that a buyer is willing to pay for a share of stock or other security. The ask price represents the minimum price that a seller is willing to take for that same security. A trade or transaction occurs when a buyer in the market is willing to pay the best offer available—or is willing to sell at the highest bid.

The difference between bid and ask prices, or the spread, is a key indicator of the liquidity of the asset. In general, the smaller the spread, the better the liquidity.

Understanding Bid and Ask

The average investor contends with the bid and ask spread as an implied cost of trading. Most investors and retail traders are "market takers," meaning that they usually will have to sell on the bid (where someone else is willing to buy) and buy at the offer (where someone else is willing to sell).

For example, if the current price quotation for the stock of ABC Corp. is $10.50 / $10.55, investor X, who is looking to buy A at the current market price, would pay $10.55, while investor Y, who wishes to sell ABC shares at the current market price, would receive $10.50.

Who Benefits from the Bid-Ask Spread?

The bid-ask spread works to the advantage of the market maker. Continuing with the above example, a market maker who is quoting a price of $10.50 / $10.55 for ABC stock is indicating a willingness to buy A at $10.50 (the bid price) and sell it at $10.55 (the asked price). The spread represents the market maker's profit.

Bid-ask spreads can vary widely, depending on the security and the market. Blue-chip companies that constitute the Dow Jones Industrial Average may have a bid-ask spread of only a few cents, while a small-cap stock that trades less than 10,000 shares a day may have a bid-ask spread of 50 cents or more.

The bid-ask spread can widen dramatically during periods of illiquidity or market turmoil, since traders will not be willing to pay a price beyond a certain threshold, and sellers may not be willing to accept prices below a certain level.

The Bottom Line

Most quotes in securities markets are two-sided, meaning they come with both a bid and an ask. The bid is the highest price at which someone is willing to buy the security, the ask or offer is the lowest price at which someone is willing to sell it. Together, the bid and ask make up the price quote, with the distance between the bid-ask spread an indicator of a security's liquidity (the tighter the spread, the more liquid). Quotes will often also show the amount of the security available at both the current best bid and ask prices. Most retail traders and investors must sell on the bid or buy on the offer, while market makers set the bid and offer prices where they are willing to buy and sell.