Buy/Sell Volume Indicator: Formula, Settings and How to Read It
Buy/Sell Volume plots the two halves of delta as separate series: the volume that traded into the ask and the volume that traded into the bid, summed across every price level of the bar. Where delta shows the net result, this indicator shows both legs that produced it.
Senzoukria · Indicators · Updated September 2026
Buy/Sell Volume ships with the Senzoukria desktop app, in the Volume group of the indicator catalogue. It is drawn in its own panel below the chart.
What Buy/Sell Volume measures
For each bar the indicator sums buy volume and sell volume across the bar's price levels and draws them as two lines. Delta is the difference between those two sums, so a bar of 2,000 against 1,800 and a bar of 200 against 0 carry the same delta of 200 while describing completely different activity — one is a heavy two-sided fight, the other a thin one-way print. The classification comes from the aggressor side recorded at each price level, not from the direction of the close.
The formula, as implemented
This is not a description of how the indicator is usually defined elsewhere — it is what the shipped code computes, documented next to the implementation:
Volume acheteur et vendeur — 2 lignes : Σ buyVolume et Σ sellVolume des niveaux de chaque barre (canon : delta = buy − sell, ici les deux jambes séparées).
How to read it
- Both legs rising together is participation: more contracts crossing in both directions, which is a different event from one side taking over.
- One leg collapsing while the other holds is the shape behind most large delta readings — identify which leg actually moved before attributing the bar to buyers or sellers.
- A bar whose two legs are nearly equal has a delta near zero and can still be the heaviest bar on the screen. Total volume and delta answer different questions.
- At a level being retested, compare the legs with those of the first test; a second test that trades far less on the same side describes interest that did not return.
- Raise the smoothing only to compare regimes. On the raw setting each spike belongs to one bar and can be read in the footprint.
Parameters and defaults
Buy and sell colours default to teal (#26a69a) and red (#ef5350). Smoothing is 1 by default — raw per-bar sums — and raising it up to 200 averages both legs over that window, which helps when comparing participation between periods but erases single-bar events.
| Parameter | Type | Default | Range |
|---|---|---|---|
| Smoothing | number | 1 | 1 – 200 |
What it does not show
The split depends entirely on the feed classifying each trade's aggressor side; a source without that information cannot produce these two legs, and feeds that infer the side from price ticks misclassify trades at unchanged prices. Aggressive volume is not conviction: a large buy leg fully absorbed by resting offers moves nothing, and this pane cannot show that absorption. Market data for futures is billed by the provider separately from the Senzoukria subscription, and crypto pairs in the application are read for analysis only.
Using it in Senzoukria
Add it from the Indicators panel of any footprint chart or candle chart. It runs on futures data from Rithmic or Databento and on crypto pairs from Binance and Bybit, on the same engine — the calculation does not change with the venue, only the data feeding it does. Market data subscriptions are billed by the provider, separately from the app.
Related indicators
- Volume — Volume
- Average Trade Size — Volume
- Volume ROC % — Volume
- Relative Volume — Volume
- Trade Count — Volume
- Level Count — Volume
See the full indicator library, or start with the order flow guide if you are new to reading aggression, delta and absorption.
Frequently asked questions
- What is the difference between buy/sell volume and delta?
- Delta is a single number, the buy volume minus the sell volume of a bar. Buy/Sell Volume keeps the two sums apart and plots them as two series. The same delta can come from a heavy two-sided bar or from a thin one-sided bar, and only the split shows which.
- How is a trade classified as buy or sell volume?
- By the aggressor side: a trade that lifts the offer counts as buy volume, one that hits the bid counts as sell volume. The application uses the side recorded at each price level of the bar, so the classification is only as good as the data feed that supplies it.
- Why can a bar with a small delta still matter?
- Because delta is a difference. A bar in which 5,000 contracts traded on each side has a delta of zero while representing 10,000 contracts of two-sided activity, often around a level where large resting orders are being worked. Reading the legs separately keeps that bar visible.