A candlestick chart on its own tells you where price has been. An order book heatmap tells you what price had to get through to be there — and what is waiting above and below it right now.

The chart has three layers

Every order book heatmap is really three different data sources drawn on the same grid, and it helps to keep them apart in your head.

1. Resting liquidity — the heat

The coloured background is the order book itself: limit orders waiting at each price. Brighter means more size resting there. Nothing in this layer has traded. It is a picture of what people say they are willing to do.

2. Executed trades — the bubbles

Each trade that actually happened is drawn at its price and time, sized by how much went through. This is the aggressive side of the market: someone who wanted in or out now, and paid the spread to get it.

3. Price — the line, the candles or the footprint

The thin line walking through the middle is the mid price. On its own it is the least interesting layer. It becomes interesting when you can see what it walked through. In Swiftedge Depth the same layer can also be drawn as candlesticks, or as a footprint chart that splits each candle into the buying and selling at every price.

How to read it

Three patterns come up constantly, and they are the reason the chart is worth looking at.

A wall that holds

A bright band sits above price. Trades hit it repeatedly — you see bubbles stacking at that level — and the band stays bright. Someone is refilling. Price stalls and turns away. The seller had more size than the buyers had aggression.

A wall that breaks

The same picture, except the band dims as the bubbles land on it, and then vanishes. Price continues through. The order was consumed rather than refilled, and whatever was behind it was thin.

A wall that disappears untouched

The band vanishes without trades landing on it. Nobody bought it — it was pulled. That tells a different story entirely, and it is invisible on a normal chart.

The honest caveat. A large resting order is not a promise. It can be cancelled in a millisecond, and a market can be moved by orders that were never meant to be filled. Size that gets traded is evidence. Size that is only displayed is a claim.

Why the time axis matters

A depth chart — the ladder you see on most exchanges — shows the book right now. A heatmap shows the same book over time. That difference is the whole point: you can see that the level which is stopping price today has been defended for two hours, or that it appeared thirty seconds ago.

Reading the scale honestly

Most heatmaps compress the price axis into bins and the colour scale logarithmically, because the largest orders are often hundreds of times bigger than the typical one. That means colour is relative, not absolute. Before you conclude that a level is huge, check the actual size — a good tool shows it in the units the market trades in.

See it on live data. Swiftedge Depth shows the Bitcoin futures order book as a heatmap with every trade as a bubble, free in the browser and with no sign-up.

Common questions

What does an order book heatmap show?

It shows resting limit orders — bids and asks that are waiting to be filled — as colour on a price and time grid. Bright areas are large resting size at that price. As time moves left to right, you see the same orders sitting, growing, or disappearing.

What is the difference between a heatmap and volume?

A heatmap shows intent: orders that are waiting. Volume shows what actually traded. Both matter, and they answer different questions. Size that sits and is never traded is very different from size that gets eaten in seconds.

Is an order book heatmap useful for crypto?

Crypto order books are public and update continuously, which makes them well suited to this kind of chart. Bitcoin futures on a large exchange update several times a second, so a heatmap can show a level forming and being taken out within the same minute.

Market data and descriptive analysis only. Not financial advice.

Cumulative volume delta, or CVD, is a running total of aggressive buying minus aggressive selling. It answers a simple question: since the start of the day, have traders who cross the spread been mostly buying or mostly selling? This guide explains how it is built, how to read it next to the order book, and what two and a half years of Bitcoin data say about what it can and cannot tell you.

From one trade to CVD

Every trade has two sides: a resting limit order (the maker) and an order that crossed the spread to hit it (the taker, or aggressor). If the taker was buying, the trade adds its size to delta; if the taker was selling, it subtracts. Add up the deltas from a fixed starting point and you get CVD.

delta = taker buy volume − taker sell volume (per bar) CVD = the running sum of delta since the reset (00:00 UTC in Swiftedge)

For scale: in our data a typical hour of Bitcoin perpetual futures had a delta of about 350 BTC in one direction or the other (median, 2024-2026).

CVD in Swiftedge Depth

Swiftedge Depth, 19 October 2026, three hours: the yellow CVD line over the volume bars counts aggressive buying minus aggressive selling since 00:00 UTC. Its label shows the value at the right edge of the view.

Swiftedge Depth computes CVD from every trade on Binance's BTCUSDT perpetual, using the exchange's own flag for which side was the taker. Older hours are stored with trades combined per side, which gives exactly the same sum. The line resets at 00:00 UTC and is drawn over the volume pane, on the same time axis as the heatmap, so you can see how the balance of aggressive flow changed while price met each liquidity wall. Switch Depth to the footprint chart to see the same delta per candle, in the table under the chart, and at every price inside the candle.

Why CVD and price move together

An aggressive buy order lifts offers until it is filled, and an aggressive sell order hits bids. So in the short run, buying pressure and price tend to rise together. Our data shows how strong that link is:

• Same hour: the correlation between an hour's delta and that hour's price change was 0.75, and the two pointed the same way in 77 % of hours (24,528 hours, January 2024 to October 2026).
• Stable: 0.78 in the first half of the period and 0.71 in the second.

What CVD did not do: predict the next hour

The correlation between an hour's delta and the next hour's price change was 0.002, which is zero for practical purposes, and it stayed near zero in both halves. CVD describes the move that is happening; it did not tell us about the next one.

Divergences, tested

A popular reading is the "divergence": price makes a new high but CVD does not, so buyers are said to be running out and a reversal is near (and the mirror image at lows). We tested it on every hour where the close made a new high or low of the UTC day, and compared the next four hours with and without a divergence.

New highs with a bearish divergence rose over the next four hours about as often as new highs without one, in fact slightly more often. At new lows, a bullish divergence made no difference. The pattern was the same in both halves of the period. In this data a CVD divergence on its own did not mark turning points.

Where CVD helps: reading absorption

CVD becomes more useful next to the order book. If CVD climbs steeply while price barely moves, aggressive buyers are being filled by someone passive, often a wall of resting sell orders you can see in the heatmap. That is absorption. Whether the wall then holds, is eaten or is pulled is something you see in the book, not in CVD alone. The takers, makers and absorption guide walks through it.

Limits

• One venue. Swiftedge's CVD covers Binance's BTCUSDT perpetual, the largest Bitcoin futures market, but not spot exchanges or other venues, where the balance can differ.
• The reset matters. CVD since 00:00 UTC and CVD since the London open can tell different stories about the same hour.
• Size is not intent. Aggressive selling can be a hedge, a liquidation or a position being closed; CVD counts them all the same.

See CVD on live data.Swiftedge Depth draws CVD over the volume pane, under the live Bitcoin order book heatmap and every trade. Free, no sign-up.

Common questions

Does rising CVD mean price will keep rising?

No. Rising CVD means aggressive buyers have dominated so far. In our data CVD moved with price in the same hour but said nothing about the next hour, and divergences between CVD and price did not mark reversals.

What is the difference between delta and CVD?

Delta is aggressive buying minus aggressive selling in one bar, for example one hour. CVD adds the deltas up from a starting point, so it shows the balance over the whole session.

Why is my CVD different on another platform?

Different venues, spot or futures, a different reset time, or a different rule for which side was aggressive. Swiftedge uses every trade on Binance's BTCUSDT perpetual, the exchange's own taker flag, and resets at 00:00 UTC.

Where do I find CVD in Swiftedge Depth?

It is drawn as a yellow line over the volume pane at the bottom of Depth. The CVD on/off button in the pane's corner turns it on or off, and the pane can be resized by dragging its top edge or minimized.

Market data and descriptive analysis only. Not financial advice.

We build Swiftedge, a set of free browser tools that show what happens inside the Bitcoin and Ethereum markets: where orders wait, where they trade, and where they disappear. Building them meant recording the order book four times a second, every trade, and the options market around it, for months. We started testing the popular claims about order flow against that data.

Some held up. Some did not. Here are seven of them.

1. About half of the big walls near price are pulled, not traded

We took four weeks of the Bitcoin perpetual futures book and classified every large wall (a 25 USD price level in the top 3 % of resting size that day, standing for at least six minutes) by how it ended.

Of the 244 large walls that disappeared while price was close and could be classified cleanly, 116 were pulled, not traded. The median one vanished in 0.3 seconds, 71 % within a single second, and it lost 97 % of its size in that moment. Bids and asks were pulled about equally often (55 and 61).

One example: on 18 October 2026 a bid of about 416 BTC, roughly 34 million dollars, sat at 81,960, 34 USD under price, for 30 minutes. At 11:54 UTC it was cancelled in 0.3 seconds. Over its whole life, 7 BTC had traded at that price.

Where to see it: in Swiftedge Depth a wall is a bright band; when it is cancelled the band simply stops. The daily Bitcoin report lists which walls held, which were eaten and which were pulled in each session. Full method: Bitcoin spoofing and pulled walls.

2. Distance decides almost everything

The same study showed one variable that mattered more than size or side: how far the wall was from price when it disappeared.

Walls that vanished more than 75 USD from price were cancelled 92 % of the time. A big wall far away is a statement of intent that is cheap to withdraw. A wall that price is already trading into is a different thing.

3. Price is not simply pulled toward the thickest liquidity

A common idea is that price is drawn to the biggest resting liquidity like a magnet. In 85 hours of our recordings (August 2026), the thickest resting size usually sat 100 to 250 USD or more from price, while a typical five-minute Bitcoin move was about 30 USD (90 % of them under roughly 130 USD). Most of the time, the thickest liquidity is simply too far away to be the next target.

This is also where an order book heatmap and a liquidation heatmap differ. One shows orders that are really resting in the book. The other is a model of where leveraged positions would be force-closed. Both are useful, and they answer different questions. We put both side by side: the live order book heatmap and a free Bitcoin liquidation heatmap that is checked against the real liquidations. The difference is explained in liquidation heatmap vs order book heatmap.

4. CVD describes the hour. It did not predict the next one

Cumulative volume delta (aggressive buying minus aggressive selling) is one of the most quoted order flow numbers. Over 24,528 hours of Bitcoin data (January 2024 to October 2026), an hour's delta and that same hour's price change had a correlation of 0.75, and pointed the same way in 77 % of hours.

Then we checked the next hour. The correlation between an hour's delta and the following hour's price change was 0.002. For practical purposes, zero, and it stayed near zero in both halves of the data.

CVD tells you clearly who was aggressive. It does not tell you what happens next. In Depth it is drawn over the volume pane, reset at 00:00 UTC. Details: What is CVD?

5. Most stacked imbalances get traded through

A stacked imbalance is aggressive buying or selling that outweighs the other side on several prices in a row, a pattern many footprint traders mark as support or resistance. In 41 hours of Bitcoin data, 72 % of stacked imbalance zones were traded through within five minutes, and only about 8 % were still unbroken after an hour. Bigger zones did not hold much better: six or more rows broke within five minutes 68 % of the time, against 75 % for three rows.

Depth now has a footprint chart (buying and selling at every price inside each candle, with imbalances, POC and delta) and an indicator that marks stacked imbalance zones, so you can watch them form and break. Method: Stacked imbalances explained, with data.

6. Options gamma changed volatility. Trading the walls did not work

Options dealers hedge, and when they are estimated to be long gamma, their hedging tends to dampen moves. Over 6,680 hours of Bitcoin data (January to October 2026), hours our model classed as long gamma were followed by about 19 % lower volatility in the next hour (roughly 32 versus 40 basis points).

That sounds tradable. So we tested the obvious strategy: fade price back toward the middle when it reached the options call wall or put wall, in the long-gamma regime. Over nine months it lost money after costs, and did worse than all 20 sets of random levels we compared it with.

The levels describe the options market. They are not a trading system. You can see them live in Swiftedge Options, one chain across the major options venues where row height shows the options-implied odds of settling near each strike (what options cost, not a forecast), and on Bitcoin levels today. Five guides start here: What is GEX?

7. Expiry day concentrates a lot of open interest at one minute

Bitcoin options expire at 08:00 UTC. In a snapshot on 19 October 2026, the monthly expiry on 30 October held about 162,400 BTC, roughly 13.4 billion dollars, which was 37.7 % of all open Bitcoin options. Calls outweighed puts (put/call 0.56), and options priced a move of about ±5.9 % by expiry.

Each monthly and quarterly expiry now gets its own page three weeks before, with open interest by strike, max pain and the priced move, and afterwards where it settled: 30 October 2026 expiry. Why 08:00 UTC matters: Bitcoin options expiry, explained.

The free toolbox behind these numbers

Everything above runs in the browser, free, with no account:

• Swiftedge Depth: the live Bitcoin futures order book as a heatmap, updated four times a second with at least 24 hours of history, every trade as a bubble. Price as a line, candlesticks from 1 second to 4 hours, or a footprint chart. Add VWAP, real liquidations, stacked imbalance zones, an imbalance readout, CVD, options GEX levels, Session Orbs for the Tokyo, London and New York opening ranges, Mentor (a plain-language read of structure, liquidity and order flow) and 24 drawing tools. Price and large-wall alerts, sharing any moment as an image card, and it installs as an app.
• Swiftedge Options: the live options chain with open interest by strike, live trades, call wall, put wall, gamma flip and max pain, plus alerts when Bitcoin nears a wall or crosses the flip.
• Live data pages: levels, liquidations, liquidation heatmap, funding, open interest, long/short ratio, whale trades and options expiries.
• Reports: a daily Bitcoin report written from the data for the Asia, London and New York sessions, and a weekly report every Sunday, with an RSS feed.
• Ethereum, the same way: since 20 October everything exists for Ethereum too: ETH Depth, ETH options, ETH reports, levels and liquidation heatmap.
• A free widget to put the live heatmap on your own site, and 42 free SwiftEdge indicators on TradingView.
• Guides and a glossary in plain English, several of them testing their claims against our own recordings, like the ones above.

What this is not

None of this is financial advice, and none of the findings is a buy or sell call. Several of them are the opposite: things that sounded predictive and were not. The options-implied odds describe what options cost, not what will happen. Depth is in public beta, so features change often; what changed lately is on the updates page.

What we can promise is that the numbers come from the data, with the period and the method stated, and that we show what did not work as clearly as what did.

Swiftedge is built by Swiftedge ApS in Denmark. Watch the live Bitcoin order book: swiftedge.uk

We wanted to know how often that really happens, so we measured it. This post explains how we classified every large wall in the Binance BTCUSDT perpetual order book as held, eaten or pulled, what the numbers were, and what they do not prove.

Disclosure: I work on Swiftedge, a free browser tool that shows the live Bitcoin order book as a heatmap. The data below comes from our own recordings. The full write-up is on our site.

The data

• Our own recording of the Binance BTCUSDT perpetual order book, four snapshots per second, plus every trade.
• Period: 22 September to 18 October 2026 (about four weeks).

Step 1: what counts as a "large wall"

A wall is a 25 USD price level whose resting size is in the top 3 % of that day, and which stands for at least six minutes. The six-minute rule removes the flicker of orders that appear and vanish within seconds.

A wall disappears at the moment its size falls below 30 % of its earlier size and stays there.

Step 2: held, eaten or pulled

The key idea is to look only at the trades at the wall's own price. If size vanished from the book, either someone traded against it or someone cancelled it. The trade tape tells you which.

• Eaten: at least half of the size that disappeared actually traded.
• Pulled: at most 10 % traded, the wall was at least 3 USD from price, and at most 10 % traded over its whole life.
• Held: price reached the wall, at least 5 BTC traded into it, most of it was still there afterwards, and price then turned at least 60 USD away.
• Mixed: everything in between. Slow fades and walls with incomplete data were left out.

801 large walls ended while price was within 0.4 %. 244 of them could be classified cleanly, and the results below describe those 244.

The results

A few things stood out:

• Pulled walls go fast. 71 % vanished within one second, and the median one lost 97 % of its size in that moment.
• Pulled walls rarely see a trade. In at least nine of ten cases, not a single BTC traded at the wall's price during its life.
• They were not fleeting: a pulled wall had typically stood for 13 minutes (middle half: 7 to 23 minutes) before it was cancelled.
• Bids and asks were pulled about equally often (55 bids, 61 asks), and size did not change much: 41 % to 58 % of walls were pulled in every size group.

Distance is the strongest clue

For the 186 walls that were still in front of price when they disappeared:

Of walls more than 75 USD from price, 92 % were pulled. Close to price, walls mostly get traded into. Far from price, they mostly get cancelled before price ever arrives.

And real "holds" were rare: of 172 walls that price came within 37.5 USD of, only 9 met every hold condition.

One example

On 18 October 2026, a bid wall of about 416 BTC (roughly 34 million dollars) sat at 81,960, about 34 USD below price, for 30 minutes. At 11:54:02 UTC it was cancelled in 0.3 seconds. Over its whole life, only 7 BTC had traded at that price.

What this does not prove

• A cancelled order is not proof of spoofing. Market makers and large traders cancel and re-place orders all the time, for many reasons. The order book shows what happened, not why.
• Only 244 of 801 walls could be classified cleanly.
• It is one exchange's perpetual market over four weeks.
• It is descriptive and looks backwards. Nobody can tell in advance whether a given wall is real.

See it yourself

You can watch walls appear, get eaten and get pulled in real time in Swiftedge Depth: the live Bitcoin order book as a heatmap, every trade as a bubble, plus options GEX levels. It is free and runs in the browser without an account.

Market data and descriptive analysis only. Not financial advice.