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Delta Histogram — Delta, in its own panel below the chart.
What Delta Histogram measures
The value is the bar's total delta exactly as the backend aggregates it from the per-level bid and ask breakdown; the indicator consumes that figure instead of recomputing it, so the column and the number written on the footprint always agree. A positive column means market orders lifted the offer more than they hit the bid over the bar, a negative column the opposite. Colour carries the sign and nothing else, green above zero and red below with the default palette, so magnitude has to be read from the column height.
The formula, as implemented
This is not how the indicator is usually defined elsewhere — it is what the shipped code computes, documented next to the implementation:
Histogramme du delta par barre : value = totalDelta (Σ (buy−sell) des niveaux, agrégé par le backend). La couleur suit le signe — c'est la série pane du chiffre déjà affiché en overlay texte sur le footprint.
How to read it
- Read height before colour: a small green column and a large green column carry the same sign but very different amounts of aggression.
- A large column next to a small price range means aggressive orders met opposing resting liquidity rather than moving price.
- A column whose sign contradicts the candle direction is worth inspecting on the footprint itself before drawing any conclusion.
- A column near zero means buy and sell aggressor volume roughly cancelled out over the bar, which is not the same as low activity.
- Compare consecutive columns within the same session; column size scales with bar volume, so a quiet stretch and an open produce different baselines.
Parameters and defaults
The positive (#26a69a) and negative (#ef5350) colours are cosmetic defaults and change nothing in the calculation. Smoothing defaults to 1, meaning raw per-bar values; raising it up to 200 averages the series across neighbouring bars, which flattens isolated spikes and moves turning points later.
| Parameter | Type | Default | Range |
|---|---|---|---|
| Smoothing | number | 1 | 1 – 200 |
What it does not show
The histogram says nothing about the order in which trades occurred inside the bar, so a bar that was bought throughout and one that was bought only at the end can produce the same column. It cannot separate one determined participant from a crowd of small orders, which is what Delta per Trade is for. The number depends entirely on the data source classifying the aggressor side of each trade; feeds that report only aggregate volume produce no usable delta. Delta is a record of what traded, not a statement about what price will do next.
Related indicators
- Delta % — Delta
- Session CVD — Delta
- Delta momentum — Delta
- Delta min/max — Delta
- Price/Delta Divergence — Delta
- Delta % Histogram — Delta
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Frequently asked questions
- What does delta mean on a footprint chart?
- Delta is the net aggressor volume of a bar: the volume traded at the ask by buyers crossing the spread, minus the volume traded at the bid by sellers crossing the spread. A positive delta means aggressive buyers traded more contracts than aggressive sellers over that bar. It describes who paid the spread, not who was right.
- Is a positive delta bar bullish?
- Not on its own. Positive delta only means aggressive buying outweighed aggressive selling during the bar; if that buying was met by larger resting sell orders, price can close flat or lower with delta still positive. The combination of delta, the bar's price range and the resting liquidity around it carries more information than the sign alone.
- What is the difference between delta and volume?
- Volume counts every contract traded in the bar regardless of who initiated it, while delta counts only the imbalance between the two aggressor sides. A bar can have very high volume and near-zero delta when buyers and sellers crossed the spread in similar amounts. Volume measures activity, delta measures its direction.