Indicators: buy/sell flow and tape speed

The second wave of the Tape & flow group adds cumulative buy and sell volume per session, a buy/sell ratio, volume z-score, session RVOL, trade intensity, a tape speed EMA and two marker studies for climax and quiet bars.

Senzoukria · Documentation · Updated September 2026


Where to find it

Where
Chart → Indicators button → group Tape & flow
Studies
cum-buy-volume, cum-sell-volume, buy-sell-ratio, volume-zscore, session-relative-volume, trade-intensity, tape-speed-ema, climax-bars, quiet-bars
Baseline rule
Statistical detectors use the N bars strictly before the current one and a population standard deviation
Session anchor
Source convention: CME 17:00 Chicago for futures, 00:00 UTC for crypto

What each study computes

Cumulative buy volume and Cumulative sell volume sum buyVolume or sellVolume of the usable levels from the session opening and restart at 0 at every new session. If a bar carries volume without a per-price split, the running total becomes null for the rest of that session, because a cumulative figure with a missing leg would be incomplete; only the next session opening restarts it.

Buy/sell ratio divides Σbuy by Σsell for each bar: 1 is balance, 2 means twice as much aggressive buying. When Σsell is 0 the bar leaves a gap instead of an infinite value. Trade intensity is the trade count per bar drawn as a histogram from the zero baseline, the same raw metric as Trades count in the Volume group but in histogram form. Tape speed EMA is an exponential average of trades per bar (SMA seed, alpha 2/(N+1)); it does not normalise by time, unlike Tape Speed in the first wave.

Volume Z-Score is (volume − mean) / standard deviation, where the mean and population deviation are taken over the N bars strictly before the current one so that the bar does not dilute its own reference. Session RVOL divides the bar volume by the average volume at the same session offset in the N previous sessions; every one of those sessions must have a bar at that exact offset, otherwise the value is null.

Settings

Parameters declared in desktop/src/lib/footprint/series/catalog/flow2.ts
StudySettingDefaultWhat it changes
Cumulative buy volumeColor / Smoothinggreen / 1Line color; Smoothing 1 to 200 bars
Cumulative sell volumeColor / Smoothingred / 1Line color; Smoothing 1 to 200 bars
Buy/sell ratioColor / Smoothingcyan / 1Line color; Smoothing
Volume Z-ScorePeriod20 (2 to 500)Length of the preceding-bars baseline
Session RVOLSessions5 (1 to 20)Number of previous sessions in the same-offset average
Trade intensityColor / Smoothinggray / 1Histogram color; Smoothing
Tape speed EMAPeriod10 (2 to 200)EMA length in bars
Climax barsPeriod / Threshold (σ) / Color20 / 2 / orangeBaseline length, sigma multiple (0.5 to 5 by 0.5), dot color at the bar high
Quiet barsPeriod / Threshold (σ) / Color20 / 1.5 / grayBaseline length, sigma multiple, dot color at the bar low

Climax and quiet bars

  • Climax bars fire when both volume and range (high − low) are strictly above mean + k·σ of the preceding N bars. The range test is in price units and needs no tick size. A dot is drawn at the bar high.
  • Quiet bars fire when volume is strictly below mean − k·σ; the default threshold of 1.5 is looser than the climax threshold because drying-up is gradual. A dot is drawn at the bar low.
  • Both draw nothing during warm-up (fewer than N preceding bars) and, with a constant baseline, only a genuine move away from the mean triggers a marker.

Limits and pitfalls

  • Session RVOL matches sessions by exact bucket offset, which works on time-based bars. On tick, volume or range bars the offsets rarely align and the study returns null; Time-of-Day Volume in the Microstructure group uses the session minute instead.
  • Trade counts depend on what the source reports as an execution. Compare like sources and like bar types, as the study guide card for Trade intensity and Tape speed EMA states.
  • Cumulative volumes cover loaded history only; a session loaded from the middle gives a partial cumulative figure.

This page in other languages

Frequently asked questions

Why is Tape speed EMA different from Tape Speed?
Tape Speed (first wave) divides trade counts by the known closed-bar durations to give trades per minute. Tape speed EMA keeps the unit at trades per bar and smooths it with an EMA of default length 10; changing bar type changes the measure.
Why does Cumulative buy volume turn into a gap mid-session?
A bar that has total volume but no per-price levels cannot contribute a buy leg. From that bar on the cumulative value is null until the next session opening resets it to 0.

Keep reading