Order book heatmap: what it is and how to read it
Updated 2026-11-13
An order book heatmap is a picture of the order book over time. Time runs from left to right, price from bottom to top, and the brightness of each cell shows how much money in limit orders was waiting at that price at that moment. Orders that stay in place draw bright horizontal bands. The map shows where orders rested; it does not say where price will go.
What an order book heatmap shows
An order book is the list of limit orders waiting to be filled: orders to buy (bids) below the current price and orders to sell (asks) above it. A ladder shows that list at one moment. An order book heatmap lines up many moments side by side, so you can see which orders stayed, which appeared and which went away.
Each column is one moment, or a stretch of time on longer views, and each row is a narrow range of prices. A cell's brightness shows the USD of orders resting in that range at that time. On MarketTrace the scale is logarithmic: each tenfold rise in USD adds the same step of brightness, so small and large orders both stay visible on one map.
How to read it
Bright horizontal bands are orders that rested at one price for a while: below the price line they are buy orders, above it sell orders. A band ends for one of three reasons: price traded through it, the orders were cancelled, or that price fell outside the part of the book the exchange sends. Where the price line runs into the end of a band, price traded there; where it does not, the orders were cancelled or went out of reach.
Dark areas mean different things in different places. Outside the band of orders, dark means no data: the exchanges do not send that part of their books, or the archive has a gap there. It does not mean the book is empty. Inside the band, a dark cell is a price where no orders were resting at that time.
The line through the map is the mid price, halfway between the highest buy order and the lowest sell order. It is not the price of the last trade.
What it cannot show
It shows totals, not single orders. A bright cell can be one large order or many small ones, and the map cannot tell who placed them.
It shows only the part of each book the exchange sends, the part nearest the price. On BTC and ETH that is a narrow band; orders further away exist but are not in the data.
It cannot tell a filled order from a cancelled one. The only clue is whether price reached the level when the band ended. It is also built from snapshots taken every second or every few seconds, so orders that appear and vanish between two snapshots never show.
Resting orders are not a promise: they can be cancelled at any moment. A band says where orders were, not where price will stop.
How MarketTrace builds its order book heatmap
MarketTrace combines the order books of Binance, Bybit, OKX and Hyperliquid into one map for each coin it tracks. Hyperliquid's book comes in coarser price steps and reaches much further from the price, so its orders are cut to the price band the other exchanges reach; shown on its own in Pro, it is not cut.
The free map is live: the last 15 minutes, shown as soon as the page opens and updated once a second. Pro reads an archive of the combined book, saved every 5 seconds and kept for 30 days, with windows from 1 hour to 30 days. The exact feeds, price steps and rules are on the methodology page.
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Frequently asked questions
What is an order book heatmap?
A chart of the order book over time. Time runs from left to right, price from bottom to top, and each cell's brightness is the USD of limit orders resting at that price at that moment. Buy orders sit below the price line and sell orders above it.
What do the bright bands mean?
A bright horizontal band is a large amount of money in orders that stayed at one price for a while. It shows where orders were waiting, not where price will go: the orders can be cancelled at any moment, and the band then ends without price ever reaching it.
Why does a band end?
For one of three reasons: price traded through it, the orders were cancelled, or that price fell outside the part of the book the exchange sends. If the price line reaches the level where the band ends, price traded there; if it does not, the orders were cancelled or went out of reach. The map cannot tell how much was filled and how much was cancelled.
Why are parts of the map dark?
Outside the band of orders, dark means no data: the feed does not reach that price, or the archive has a gap there. It does not mean the book is empty. Inside the band, a dark cell is a price where no orders were resting at that time.