On this page
Buy/sell ratio — Tape & flow, in its own panel below the chart.
What Buy/sell ratio measures
Both sums cover the usable price levels of the bar, so the ratio reflects the whole bar rather than a region of it. It is a scale-free view of the information a delta histogram carries: delta reports the net in contracts, this reports the proportion. When a bar has no aggressive selling at all, the result is left empty instead of being reported as infinite, and a bar with no usable levels carries no information either. Keeping those two cases empty rather than substituting a number is the reason to prefer the plotted ratio over one computed by hand.
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:
Ratio buy/sell par barre : Σbuy / Σsell (niveaux exploitables). 1 = équilibre, 2 = deux fois plus d'agression acheteuse. Σsell = 0 → trou (null) : x/0 n'est pas « ∞ », c'est « pas de dénominateur » — et une barre sans niveau exploitable (0/0) n'a aucune information non plus.
How to read it
- Read the distance from 1 in both directions: 2 and 0.5 are the same imbalance mirrored, so a symmetric mental scale, or a log view, avoids overweighting the upside.
- Values close to 1 across a run of bars describe two-sided trade, which is what a rotation looks like in flow terms.
- A large ratio on a bar with small total volume is a proportion, not a push. Check the bar's volume before reading anything into it.
- Compare consecutive bars rather than absolute levels: the direction of change is usually more useful than the value itself.
- Gaps in the plot are bars with no sell volume to divide by, which happens on very thin or single-sided bars.
Parameters and defaults
No period and no threshold exist here — the ratio is defined entirely within a single bar. Colour and smoothing length are all there is to set, and with smoothing at 1 nothing is averaged. A longer smoothing turns the spiky per-bar ratio into a slower flow-balance line, easier to read on low intervals and slower to react.
| Parameter | Type | Default | Range |
|---|---|---|---|
| Smoothing | number | 1 | 1 – 200 |
What it does not show
The ratio normalizes size away, so it cannot distinguish a heavy imbalanced bar from a quiet one with the same proportion, and it should be read next to volume. It depends on trades being labelled by aggressor side; without that classification the ratio is not meaningful. It carries no information about where in the bar the trades happened, which is the gap the aggression and pressure ratios fill. And an imbalance is a description of what traded, not evidence that price will follow it.
Related indicators
- Tape Speed — Tape & flow
- Diagonal Imbalances — Tape & flow
- Stacked Imbalances — Tape & flow
- Absorption Score — Tape & flow
- Unfinished Auctions — Tape & flow
- Effort vs Result — Tape & flow
This page in other languages
Frequently asked questions
- What is a normal buy/sell ratio value?
- Balance is 1: the bar traded as much aggressive buying as selling. What counts as a meaningful deviation depends on the instrument, the bar interval and the session, so the reference should be the recent distribution on the same chart rather than a fixed number.
- Why does the buy/sell ratio leave gaps in the plot?
- Because a bar with no aggressive selling has no denominator. Dividing by zero is not treated as an infinite ratio here, it is treated as an absent measurement, so no point is plotted. Bars with no usable price levels are left empty for the same reason.
- Is the buy/sell ratio the same thing as delta?
- They come from the same two numbers but answer different questions. Delta is buying minus selling, expressed in contracts, so it grows with activity. The buy/sell ratio is buying divided by selling, so it is scale-free and comparable between a busy bar and a quiet one, at the cost of hiding size.