Footprint chart explained: reading bid × ask

Open a footprint chart for the first time and the urge is to close it again. It looks like a spreadsheet glued onto a candle. Hundreds of numbers, two colors, no obvious place to start.

What is usually missing is someone telling you which two numbers to read first, and why the rest can usually wait.

What a footprint actually is

Take a normal candle. It tells you four prices: open, high, low, close. A footprint keeps the candle and opens it up. It splits the bar into its price levels, one row per tick (or per group of ticks), and at each row it shows how many contracts traded there and on which side.

“Which side” is the whole point. As explained in what order flow trading is, every trade has an aggressor: someone who sent a market order and crossed the spread. The footprint sorts the volume at each price by that aggressor.

Bid × ask: the two numbers that confuse everybody

Each row usually shows two numbers side by side: bid × ask.

• The left number (bid) is the volume that traded on the bid. That means aggressive sellers: market sell orders that hit resting buy orders.
• The right number (ask) is the volume that traded on the ask. That means aggressive buyers: market buy orders that lifted resting sell orders.

Read that twice. “Bid volume” does not mean buyers. It means sellers who were impatient enough to hit the bid. A large share of footprint misreadings comes from this single inversion.

One candle, read slowly

Here is a made-up candle on NQ, five levels tall. The prices are invented to keep the arithmetic easy.

Start at the extremes. They hold most of the information.

At the low, 100.00: 150 contracts sold aggressively and only 10 bought. Sellers pressed hard at that price. And yet the low is 100.00. Not one contract traded below it. Resting bids soaked up all 150 lots without giving way, which is absorption in its simplest form.

At the high, 101.00: 4 sold, 0 bought. Buyers did not lift a single contract at the top. The rally simply ran out of people willing to pay up. Some traders call a zero on one side of the extreme a finished auction: the market found the price where one side stopped showing up.

In the middle, 100.50: 190 lifted against 45 hit. This is where the buyers actually committed. It is also the level with the most total volume (235 contracts), which makes it the candle’s POC, the point of control.

Now the candle has a story. Sellers tried the low and got absorbed, buyers pushed through the middle, and the push faded at the high without anyone chasing. A plain green candle says none of that.

Delta: the one-number summary

Add up the ask column (332) and the bid column (284). The difference, +48, is the candle’s delta: net aggressive buying. Delta is the fastest single number to check, but it hides location. Forty-eight contracts of net buying at the low of a candle say something very different from the same 48 bought at the high. Always look at where the delta was built, not only its total.

Diagonal imbalances

People tend to get lost at this point, so take it slowly.

At any instant, the best bid and best ask sit one tick apart. If the bid is 100.25 and the ask is 100.50, an aggressive buyer trades at 100.50 and an aggressive seller trades at 100.25. The two trades happen at the same instant and still land on different rows.

So to compare buyers and sellers fairly, you compare the ask at one price with the bid one tick below it. That is the diagonal.

In the example: ask at 100.50 is 190; bid at 100.25 is 55. That is about 3.5 to 1. With a common threshold of 3:1, the footprint flags 100.50 as a buy imbalance. When several imbalances in a row appear on the same side (three consecutive prices, for instance), traders call it a stacked imbalance: aggression that kept going level after level instead of a single burst.

Imbalances are useful. They are also the most overrated part of the footprint. In a fast NQ session you can find imbalances on nearly every candle. What I look for is an imbalance at a price that matters (a prior high, a value area edge, a stacked run that later becomes support) and what the market did when it came back there.

Reading order that works

When a candle closes at a level you care about, read it in this order:

1. The extremes: what traded at the high and at the low, and on which side.
2. The POC: where inside the bar the volume concentrated.
3. The delta: who was net aggressive, and was it built at the top or the bottom.
4. The imbalances: only if the first three already make the candle interesting.

Four steps, a few seconds. With practice it becomes a glance.

Three ways to misread it

It needs volume. In quiet overnight hours, rows with 3 and 5 contracts mean nothing. A pattern printed right after the New York open and the same pattern in the middle of the New York night carry very different weight.

The numbers are relative. A 150-lot bid at the low is heavy on a slow ES morning and ordinary in the first minutes of an NQ session. Compare a level with the candles around it, not with a number you memorized.

And it depends on how the bar is built. A one-minute footprint, a Renko footprint and a tick-based footprint split the same trades differently. None is wrong, but a pattern you learned on one-minute bars can look different on a tick chart, or not show up at all.

The footprint in EliteXCharts

The EliteXCharts footprint shows bid × ask per level with separate delta and volume columns, outlines the POC of each candle, draws the 70% value area per candle, and marks diagonal imbalances with a ratio you configure, with stacked imbalances getting a thicker border. It works on time, Renko, tick and delta candles, and you can merge several price levels into one cell (tick aggregation) so the footprint stays readable when NQ is moving fast. Once the layout fits how you read, you save it as the default for every chart.

For the long version, with dozens of real examples, the free footprint course covers the reading pattern by pattern.

Futures trading involves substantial risk of loss and is not suitable for every investor. The candle in this post is a made-up example for teaching.