Glossary · Orderflow
A stacked imbalance is three or more consecutive price levels on a footprint chart where aggressive trading on one side exceeds the other by a set ratio — commonly 3:1 or more. It signals one-sided force building through the order book, and a stack of them is frequently a precursor to a breakout in that direction.
Where a single imbalanced level is noise, a stack — buyers lifting the offer at level after level after level — shows committed aggression that the passive side isn't matching.
A footprint chart shows the bid-traded and ask-traded volume at every price inside a bar. An 'imbalance' compares those volumes diagonally — the ask volume at one level against the bid volume one level below — and flags it when one side beats the other by the chosen ratio (3:1 and 4:1 are common thresholds).
When that imbalance repeats on three or more consecutive levels in the same direction, it's 'stacked'. The diagonal comparison matters: it captures aggressors repeatedly reaching across the spread and getting filled higher (or lower) without the other side pushing back.
A run of stacked buy imbalances into a fresh high is classic breakout fuel: aggressive buyers are paying up and finding no resistance. Traders use it as confirmation that a move has real participation behind it rather than drifting on thin volume.
But the same pattern into a level being defended can be a trap. If those stacked imbalances run straight into absorption — a large passive seller eating every aggressive buy without price advancing — the aggression is being spent, not rewarded, and a reversal often follows. The stack tells you there's force; what happens at the level tells you whether it works.
A stacked imbalance is strongest read alongside cumulative delta (is the aggression actually moving price?), the resting size on the DOM (is anyone absorbing it?), and the level it's occurring at (is it pushing into a gamma wall or prior structure?).
Sharpnel highlights stacked imbalances automatically on the footprint and renders them next to the DOM and tape — so you see the force and whether it's being met, on one chart.
Typically a 3:1 or 4:1 dominance of aggressive volume on one side of the diagonal comparison, repeated across three or more consecutive price levels. The exact ratio and minimum run length are usually configurable.
It's directional with the aggression — stacked buy imbalances are bullish pressure, stacked sell imbalances bearish. But context decides: into open space it's a breakout cue; into absorption at a defended level it can mark exhaustion and reversal.
They're opposite tells. A stacked imbalance is aggression stacking unopposed (force building); absorption is aggression being soaked up without price moving (force being met). A stack running into absorption is the classic reversal setup.
On a footprint chart with imbalance highlighting enabled. Sharpnel marks qualifying stacks automatically, on the same chart as the DOM and tape so you can judge whether the aggression is being absorbed.
Sharpnel flags stacked imbalances on the footprint automatically — next to the DOM and tape, so you see the force and whether it's being absorbed in one place. Free Explorer tier on 15-min delayed data.
