Market depth
Market depth is how much buy and sell interest sits in the order book at different prices. The deeper the market, the more you can buy or sell without moving the price much.
How it works
The order book lists individual orders; depth is their cumulative size as you move away from the current price. On a depth chart the green "wall" of bids is on the left and the red wall of asks on the right. Tall, steep walls mean dense liquidity.
Depth is often measured as order volume within ±1% or ±2% of the mid price. If there is $5M of orders within 1%, a $100,000 market order barely moves the price. If there is only $50,000, the same order chews through the book and causes heavy slippage.
Traders check depth before large trades and to spot levels with big orders. But big orders can be fake and pulled a second before price arrives (spoofing). So depth is a hint, not a guarantee.
BTC asks in the book: 0.5 BTC at $60,000, 1 BTC at $60,050, 2 BTC at $60,150. You market-buy 3 BTC. You pay 0.5 × 60,000 + 1 × 60,050 + 1.5 × 60,150 = $180,275, an average of about $60,092, which is $92 above the best ask because the book is thin.
The mistake is judging a coin's liquidity only by its 24-hour volume. Volume can be inflated while real depth near the price is tiny. Before a big trade, open the order book, see how much size sits within 1–2% of the price, and if depth is thin, split the order or use limit orders.
Questions and answers
What is market depth in simple terms?
It is the amount of buy and sell orders near the current price. A deep market absorbs large trades without the price moving much.
How do I read a market depth chart?
The left side is cumulative buy orders, the right side cumulative sell orders. The taller and steeper the walls near the middle, the more liquidity at the current price.
What is the difference between market depth and volume?
Volume is how much already traded over a period. Depth is how many orders are in the book right now, meaning how much can fill without moving the price.
Related terms
Read next
Which order fits when.
Read →Market makerA market maker is a trader or firm that keeps both buy and sell orders in the market at all times, providing…
Partner links are marked. If you sign up through them, we may earn a commission at no cost to you. Details
Updated: 2026-10-19