What Bid and Ask Mean
Every tradable market quotes two prices at any moment. The bid is the highest price a buyer is currently willing to pay. The ask (sometimes called the offer) is the lowest price a seller is currently willing to accept. When you sell at market, you typically receive the bid. When you buy at market, you typically pay the ask. The gap between the two is known as the spread, and it represents an implicit cost of trading that exists in stocks, forex, CFDs, options, and crypto alike.
Why It Matters
Bid and ask prices matter because they determine the real price you transact at, not the single "last price" often shown on charts. In liquid markets, the spread may be tiny; in thin or volatile markets, it can widen sharply, making every round trip (buy then sell) more expensive. Traders who ignore the bid-ask spread often underestimate their true costs, especially when trading frequently or in small increments. Understanding both sides of the quote also helps you read market liquidity: a narrow, deep quote usually signals an active market, while a wide quote suggests fewer participants or higher uncertainty.
A Simple Example
Suppose a currency pair is quoted with a bid of 1.1000 and an ask of 1.1002. If you buy at market, you pay 1.1002. If you immediately sold, you would receive 1.1000, locking in a small loss equal to the spread even though the market has not moved. That two-point gap is the cost of immediacy. The same logic applies to a stock quoted 50.00 bid / 50.05 ask: buying and instantly selling would cost roughly 5 cents per share before any commissions.
Common Mistakes
- Judging value from the last traded price alone. The last trade may be stale; the live bid and ask show what you can actually deal at now.
- Ignoring spread widening. Spreads often expand around news releases, market opens and closes, or in illiquid instruments, raising costs precisely when volatility is highest.
- Using market orders in thin markets. A market order can fill far from the displayed quote when the order book is shallow; limit orders give more price control.
- Comparing platforms without checking quoted spreads. Headline commissions are only part of the picture; the typical spread you actually receive can matter just as much.
What to Verify Before Acting
Before trading, check the live bid and ask sizes, not just the prices, since displayed quantities show how much can trade at each level. Compare typical spreads across the instruments and times of day you plan to trade, and factor them into your expected costs using a resource like our cost of trading tool. If you are evaluating where to trade, spread quality and execution practices vary between providers, so review how quotes are sourced and read independent broker reviews as part of your research. Nothing here is personalized advice; verify current quotes and account terms directly with your provider before placing orders.