The bid is the highest price a buyer is willing to pay for a security at a given moment. On a trading screen, the bid is the price you can typically sell at straight away, at least for the quantity shown next to it.
The bid sits opposite the ask in a live quote. Together they form the bid-ask spread, which changes as orders arrive, trade and cancel. The best bid is the top buying price in the market, and there can be deeper bids at lower prices further down the book.
What does the bid tell you on a quote?
Most platforms show a Level 1 quote with two numbers: bid and ask. If you see 250.10 bid and 250.14 ask, buyers are willing to pay 250.10 and sellers are willing to accept 250.14. The difference of 0.04 is the spread. A size often sits next to each price, such as 250.10 x 800, which indicates up to 800 shares are bid for at that price on that venue or across venues your feed consolidates.
In an order book view, bids are listed from highest to lowest. The top line is the best bid, sometimes called the inside bid or top of book. In many markets, quotes follow price-time priority. That means a higher price gets ahead in the queue, and at the same price the earliest order has priority.
The idea is the same across asset classes. In crypto order books you will see green bid levels stacked below the midpoint, with sizes that change by the second. In spot FX, a quote like EUR/USD 1.1000/1.1002 shows 1.1000 as the bid and 1.1002 as the ask, which is the rate you can sell or buy the base currency at, respectively.
Depending on your provider and country, the bid you see may be the best price on one venue or a consolidated best across several. Some platforms also show Level 2 depth so you can gauge how much demand sits just below the top price. Exact displays and depth availability vary by provider.
How bids get into the market and how matching works
Bids are created by buy orders. A limit buy order tells the market the maximum price you will pay. If that price is below the current ask, your order rests on the bid side and adds liquidity. If your limit equals or exceeds the ask, it trades immediately against the available sell orders.
Market makers and liquidity providers also post continuous bids to keep markets tradable. Their quotes may update many times a second as they manage inventory and risk.
Most order books match using price-time priority:
- Highest bid gets first in line to trade with incoming sells.
- At the same price, the oldest resting order trades first.
- Orders can be partially filled if there is not enough size at one price.
Example: three buy limits rest at 9.98 for 500 shares, 9.97 for 800 and 9.95 for 2,000. A new buyer places 9.98 for 300. They join the 9.98 queue behind the earlier 500. When a seller hits the bid at 9.98 for 600 shares, the first 500 are filled from the older order and 100 from the newer one, leaving 200 resting at 9.98.
What happens when you sell to the bid
When you submit a market sell order, you trade with the bids that already exist. If your order is larger than the size at the best bid, you will sweep down to lower bid levels until your full size is executed. That creates slippage, which is the difference between the price you expected and the average price you actually received.
Imagine the order book shows:
- 10.00 bid for 600 shares
- 9.99 bid for 400 shares
- 9.98 bid for 2,000 shares
You sell 1,500 shares at market. Your fills would be 600 at 10.00, then 400 at 9.99, then 500 at 9.98. Your average sale price is 9.993. If you had used a limit sell at 10.01, you would have joined the ask side at 10.01, offering liquidity to buyers. That might have achieved a better price, but with the risk of not filling quickly or at all.
Stops that trigger as market orders will also hit the bid when selling. In fast moves or thin markets, the price can gap through levels, which is why the average execution may be away from the last traded price you saw.
The bid-ask spread and trading costs
The spread is the gap between the bid and the ask. It is a real cost if you need immediate execution. A buyer who takes the ask pays over the bid, and a seller who hits the bid receives less than the ask. The wider the spread, the higher this implicit cost of immediacy.
Spreads tend to be tighter in liquid names with active two-sided interest and larger order book depth, and wider in less-traded securities, outside regular hours and during volatile periods. Tick size rules set the minimum increment between the bid and ask, which shapes how tight spreads can be. In some markets the minimum tick is small relative to price, which allows narrow spreads. In others it is larger, which can keep the inside market a little wider.
Many traders use the midpoint, which is the simple average of bid and ask, to benchmark execution. Price improvement means getting a fill inside the spread, such as selling above the bid or buying below the ask. Whether that is possible depends on the venue, counterparty behaviour and your order type. Fees, rebates and routing can also affect net outcomes and vary by provider.
Other uses of bid: auctions and takeover bids
The word bid also appears in a few different contexts.
- Opening and closing auctions. Exchanges often run an auction at the start and end of the day, and sometimes around halts. During these periods, you may see indicative bid and offer interest that helps set a single clearing price for the batch. This is different from continuous two-sided trading.
- Takeover bid. In corporate newsflow, a company may make a bid to acquire another. Here, bid means an offer to buy the entire company, not a standing buy order in an order book. The share price will often move toward the offer terms if investors think the deal will complete.
- Bond and OTC markets. Less transparent markets sometimes run processes like BWIC and OWIC. A dealer may say a security is bid-only if there are buyers but no firm sellers at that moment, or post bid wanted to solicit prices.
Quick comparisons
| Context | What bid refers to | Example |
|---|---|---|
| Order book quote | Highest live buy price you can sell to now | 250.10 bid x 250.14 ask, 1,200 shares bid at 250.10 |
| FX quote | Price to sell the base currency | EUR/USD 1.1000/1.1002, bid is 1.1000 |
| Takeover news | An offer to acquire a company | Bid announced at 12.50 per share, subject to approvals |
However you see it, the bid anchors the sellable side of the market. Watching price, size and how the bid holds or gives way can tell you a lot about demand and how easily you can execute without moving the price.