A bright heatmap band can still vanish
Binance futures · BTCUSDT · FlowMap Chart
A bright band on the liquidity heatmap looks like a wall. It is only size that was sitting. That size can leave before price gets there.
This note is that gap: what the bright band shows, and why it can go dark. How to read the heat itself is in how to read the FlowMap Chart on BTCUSDT.
What a bright band is
Each heat column is a snapshot of the book. Color at a price means limit size was sitting there. Brighter usually means more size in that window. A band that stays across columns is size that kept showing up at that price.
Above the last price those bands are mostly sell limits. Below it, buy limits. The picture is history of the book on Binance futures BTCUSDT — not a liquidation map, and not a candle.
Why it can vanish
A limit can be cancelled. The trader who left the size can pull it. When that happens, the next heat columns go dark at that price. The bright band ends. Nothing traded through it. The size left.
That pull often shows up just before price arrives. The band looked like support or resistance. Then it is gone, and the book is thinner than the old heat suggested.
Size can also vanish by trading. Market orders hit the row and take the size. That is a different story: prints (bubbles) into the band, and the row shrinks because it filled — not because it was cancelled. Absorption is when hits keep coming and price still does not go through. That case is what absorption is.
Heat is history. COB is now.
The heatmap remembers where size sat. COB is the ladder right now. A bright band in the past can sit next to an empty row on COB. Trust the live ladder for what is still waiting. Use the heat to see what was there and whether it held or faded.
Bid and ask size on that ladder are explained in what bid and ask size means.
What this picture is not
Not a setup. Not a reason to fade every bright band. Not proof of spoofing — you see the pull, not the intent. Not every exchange. Binance futures BTCUSDT only here.
For learning only — not financial advice.
Watch heat and COB together on FlowMap Chart · BTCUSDT · course: heatmap.