How Do You Read Bids, Asks and Depth in a Crypto Order Book?
Direct answer
Order book basics
The bid side lists resting buy orders from the highest price down, the ask side lists resting sell orders from the lowest price up, and the gap between the best bid and best ask is the spread. Depth is the total size waiting at each level; adding it up tells you how far a market order of a given size would push the price. Big "walls" are only intentions and can be cancelled in a millisecond, so judge a book by its depth near the mid-price, how fast it refills after trades and whether volume actually executes there, not by one large number on the screen.
- Best bid = highest buy order
- best ask = lowest sell order
- Spread = best ask minus best bid
- Depth = size resting at each price
- a depth chart sums it
- A market order walks the book and fills at worse prices as it goes
- Walls can be cancelled instantly
- only executed trades are real
An order book looks like two columns of numbers flashing red and green. Read it the right way and it tells you what a trade will really cost you and how fragile the price is. Read it the wrong way and a single large order on the screen can talk you into a bad trade.
What people on X are asking
In October 2026 one account posted a beginner thread on how to read a crypto exchange order book without getting fooled, warning that a big green wall of bids is often just the top few price levels, not real buying pressure. In July another user explained that depth means the volume stacked at each level, with thick walls acting as support and thin spots letting price move easily. And in January a market account flagged a sharp drop in bitcoin order book depth on both spot and futures books while price held near $90,000.
The fact-checked answer
The parts of the book. Every exchange that runs a central limit order book shows the same structure:
- Bids: resting buy orders. The top of this column is the highest price someone will pay right now.
- Asks (offers): resting sell orders. The top is the lowest price someone will accept.
- Spread: best ask minus best bid. On a liquid BTC/USD book it is often a cent or a few dollars on a $100,000 coin; on a small token it can be several percent.
- Size: the amount of the coin waiting at each price.
- Depth: the cumulative size from the best price outward. A depth chart draws it as two curves rising from the mid-price.
Coinbase's exchange documentation, for example, publishes a "level2" feed: a snapshot of every price level with its aggregated size, followed by updates each time a level changes. Most "order book" screens are built from that kind of data.
Example: a 2 BTC market buy walking a thin book
Illustrative numbers, not live data. The order filled 2 BTC at an average of about $100,075, 0.075% above the best ask, and moved the best ask to $100,150 or beyond. On a thicker book the same order would barely move it. Tap a column header to sort.
| $100,000 | 0.5 | 0.5 | $100,000 |
| $100,020 | 0.3 | 0.3 | $100,008 |
| $100,060 | 0.4 | 0.4 | $100,025 |
| $100,150 | 0.8 | 0.8 | $100,075 |
How a market order "walks" the book. A market buy takes the cheapest ask first, then the next, until it is filled. The table shows why the price you see is only valid for the first slice of size. Our page on slippage on crypto market orders covers what that costs in practice. Before a large order, add up the sizes on the side you will hit until they cover your order; the price at that point is roughly your worst fill.
UXS decision diagram
Is that big bid wall real support?
Text version of the diagram
- Has size been traded at that level (check the trades tape)? If no: It is only an intention; treat it as a possible bluff
- Does the wall stay when price comes close? If no: Walls that vanish as price nears are often pulled or spoofed
- Does depth on that side refill after trades? If no: One-off liquidity, not a lasting buyer
- Is the same level visible on other big exchanges? If no: Local to one book; price can be pushed from elsewhere
- Otherwise: More likely real interest, but still only a probability
Diagram drawn by UXS. A simplified decision aid for education, not a recommendation.
Why walls lie. Limit orders can be cancelled at any moment before they fill. Placing large orders with the intent to cancel them before execution is called spoofing, and US commodities law (7 U.S.C. 6c) prohibits it on registered futures markets, defining it as bidding or offering with the intent to cancel the bid or offer before execution. Crypto spot markets are less policed, and many order books are on offshore venues, so large orders that appear and disappear are common. A wall tells you what someone wants you to see; the trades feed tells you what actually happened.
Thin books and sudden moves. When depth near the mid-price shrinks, smaller orders move price further. That is what the January 2026 depth warning was about: with fewer resting orders, a forced seller or a stop cascade can push price several percent quickly. Stop orders matter here because, as Investor.gov notes, a stop becomes a market order once triggered, and its fill can differ from the stop price in a fast market. Clusters of stops below a level plus a thin book is the classic recipe for a wick. Liquidations work the same way on futures books; see what a liquidation is.
What to actually read. Four numbers are more useful than the shape of the book:
- The spread, as a percentage of price.
- Depth within 1% of the mid-price on each side, in dollars.
- How quickly that depth refills after a large trade.
- Imbalance: whether one side is consistently heavier for minutes, not seconds.
Even then, the book is a snapshot. Bitcoin's daily price in Coinbase data published on FRED routinely moves more in a day than the whole visible book could absorb, because orders arrive and cancel continuously.
Decision helper
| What you see | What it usually means |
|---|---|
| Spread under 0.05% | Liquid market; market orders are cheap for small size |
| Spread over 1% | Illiquid token; use limit orders |
| Huge wall far from price | Often decoration; may be pulled |
| Depth thinning on both sides | Bigger moves on smaller orders |
| Bids refilling after selling | Real buyer absorbing supply |
Related reading: what funding rates are, market vs limit orders and why crypto crashes so hard.
Common mistakes
- Treating one large order as guaranteed support.
- Placing a big market order in a thin book.
- Reading the book on one exchange as the whole market.
- Ignoring the trades tape and watching only resting orders.
FAQ
What is the bid and ask in crypto?
The bid is the highest price a buyer is offering; the ask is the lowest price a seller will accept.
What does order book depth mean?
The total size of resting orders at and beyond each price, showing how much you can trade before the price moves.
What is a buy wall?
A large resting buy order at one price. It can be cancelled at any time before it fills.
Is spoofing illegal in crypto?
It is prohibited in US futures markets under the Commodity Exchange Act; enforcement on offshore spot exchanges is weaker.
Why does price jump through a wall?
The wall was cancelled, or market orders and liquidations consumed it faster than it was replaced.
Should beginners trade from the order book?
Use it to check spread and depth before an order; reading short-term intent from it is much harder.
Sources
- Coinbase Developer Documentation: Exchange WebSocket channels (level2 order book)
- Investor.gov: Stop order
- 7 U.S. Code 6c: Prohibited transactions, including spoofing (Cornell LII)
- FRED: Coinbase Bitcoin price (CBBTCUSD)
Facts checked November 10, 2026. X posts are cited as evidence of the question, not of the answer.