Two identical candles. Two opposite stories.

Two candles can look exactly the same on the outside — same open, same close, same wicks — and be nothing alike on the inside. One can hide buyers taking control; the other, sellers being trapped. What the candle cannot show you is exactly what the footprint was built to show: the fight, number by number.

The candle, from the inside

The footprint splits every candle by price. At each price you see two numbers: on the left, the contracts sold aggressively (hitting the bid); on the right, the contracts bought aggressively (paying the ask). Every trade has an aggressor, so the sum of all the cells equals the candle's total volume — the footprint is not extra volume, it is the same volume, classified by who forced the trade.

Imbalances: when one side crushes

When buyers vastly outnumber sellers in a zone, the footprint marks it as an imbalance. One isolated imbalance can be noise; several stacked imbalances on the same side are real initiative — someone with conviction is pushing. Professional footprints compare the numbers diagonally, across the spread: the buys at one price against the sells one tick below, because that is how the two sides actually meet.

Absorption: huge volume, zero progress

Sometimes you will see massive volume trade at one price… and price refuses to move. That is absorption: someone passive is eating all the aggression with limit orders. Heavy aggressive selling that cannot push price lower is defeated aggression — and defeated aggression is where markets often turn.

The trap: trapped traders

Put the pieces together and you get the footprint's favorite story. First, aggressive sellers push price into a low. Then, at the low, their volume gets absorbed: they keep selling hard, but price stops falling. Finally price turns — and those sellers are trapped underwater. Their forced covering (buying back) adds fuel to the bounce. The same story plays out in mirror image at highs with trapped buyers.

The candle gives you the result. The footprint gives you the fight. And that fight can be summed up in a single number — the delta. That is chapter 4.