A depth chart is a graph that visualizes an exchange’s order book by plotting cumulative limit buy orders (bids) and limit sell orders (asks) across different price levels. It helps traders quickly assess supply and demand, and how much an asset can be bought or sold at various prices without significantly moving the market.
How a depth chart is structured
Depth charts typically show two curves. The bid side represents buy interest below the current market price, and the ask side represents sell interest above it. Instead of showing individual orders, the chart aggregates them, so each point reflects the total amount available up to that price. The point where the two sides come closest is closely related to the current trading price, while the gap between them reflects the bid ask spread.
Because the chart is cumulative, steep sections suggest more liquidity concentrated near those levels, while flatter sections indicate thinner liquidity. A market with smooth, balanced curves often has deeper liquidity, meaning it can absorb larger trades with less slippage.
How traders use it in crypto markets
Depth charts are commonly used to estimate potential price impact. For example, if you want to market buy a large amount of BTC, a thin ask side near the current price suggests your order may “walk the book,” filling progressively higher sell orders and pushing your average fill price up.
Traders also look for “walls,” large clusters of bids or asks that appear as sharp steps. A buy wall can indicate strong support interest at a level, while a sell wall can suggest notable resistance. However, walls can change quickly as orders are added, removed, or strategically placed.
Depth charts matter in crypto because they translate the order book into an at a glance view of liquidity and market depth, helping participants manage execution quality, slippage risk, and timing in fast moving markets.