A footprint chart looks intimidating on first contact. A wall of numbers stacked inside every candle, two columns per row, summary statistics underneath. That visual density is the whole point: every cell encodes the volume traded at one price level, split by whether it executed at the bid or the ask. Once those numbers become legible, plain candlestick charts start to feel like reading a book with every other page torn out.
A footprint chart shows you the volume traded at every single price inside every single candle: split between aggressive buying and aggressive selling. It's the same data the exchange records, just rendered visually so a human can read it. This article walks through what every number means, how to read a single cell, and how those cells stack into a candle. By the end, you'll never look at a regular chart the same way again.
What a regular candle hides
A standard candle is a summary. It tells you where price started, where it ended, where it went, and how far. What it doesn't tell you: how price got there, who pushed it, where the heavy trading actually happened, or whether buyers or sellers were in control at each step along the way.
Two candles can look identical and represent completely different stories. A 10-tick green candle might be the result of steady, organic buying, or a desperate short squeeze where one institution was forced to cover. The shape is the same. The implications for your next trade are opposite. The footprint is what lets you tell them apart.
Anatomy of a footprint candle
Each footprint candle is built from cells: one cell per price level the candle traded through. Inside each cell, you see two numbers: bid volume on the left (volume executed at the bid price, i.e. aggressive selling) and ask volume on the right (volume executed at the ask price, i.e. aggressive buying).
Below the candle, you'll typically find summary numbers: total volume, delta (ask minus bid), and sometimes the highest-volume price within the candle. That last one (the candle POC) is gold for finding where the real fight happened.
Bid vs ask: aggressive vs passive
Here's the concept that takes a few readings to fully click. When you see "100" on the bid side of a cell, it doesn't mean 100 contracts were waiting to buy at that price. It means 100 contracts were sold aggressively at that price, meaning sellers used market orders that hit the standing bid. Same logic on the ask: a number on the ask side is volume that was bought aggressively, lifting the offer.
This is the central insight of order flow: every print has a buyer and a seller, but only one of them was the aggressor. The footprint sorts them out. If a cell shows 200 on bid and 50 on ask, sellers were pushing harder at that price. The reverse, and buyers had the upper hand.
Every transaction has both sides. The footprint tells you which side was pulling the trigger.
Reading a candle vs reading a single cell
There are two scales at which a footprint can be read. The candle as a whole: what was the total delta? Where was the POC? Is there a delta/price divergence? Then the individual cells: are there single price levels with extreme imbalance? Where did absorption happen? These two levels of reading are complementary, and beginners should start with the candle-level view before drilling into cells.
What to look for as a beginner
The footprint can feel overwhelming because there is so much information per candle. The trick is to resist trying to read everything at once. When approaching a new instrument or session, scan for three things in this order, and ignore the rest until those are clear.
Three readings, in this order
- Where is the POC of each candle? The price with the most volume is where supply and demand met most intensely. Track its movement candle by candle: it tells you where the market keeps agreeing.
- What's the delta sign and size? Strong positive delta in a green candle is healthy. Strong positive delta in a red candle (price down despite buyers pushing) is a warning: that’s absorption.
- Are there obvious cell-level imbalances? Cells where one side is 3× or more the other are footprints of aggression. Stacked imbalances across consecutive prices are institutional signatures.
The shift this creates
Once you start reading footprint, you stop seeing candles as outcomes and start seeing them as compressed stories. A doji isn't just indecision: it’s a specific pattern of buying and selling that you can actually inspect. A breakout candle isn't just "a strong move": you can see whether it was driven by aggressive buying or by absence of sellers. These distinctions matter, because the trades you make off them will be completely different.
None of the rest of this series will make sense until candle anatomy is second nature. Spend a few hours just looking at footprint candles on instruments you trade. Don’t try to draw conclusions yet. The pattern recognition will come faster than you expect.
One more thing worth saying: the footprint shows what was executed. The live intent behind those executions, the limit orders sitting on the book before they got hit, lives on the order book and is covered in the DOM series. The two views complement each other; serious order-flow readers use both.
In Part 2, we'll go deep on the single most-discussed and most-misunderstood metric in order flow: delta. What it measures, what it doesn't, why cumulative delta tells a different story than per-candle delta, and the four classic patterns that experienced traders use it to spot.