Std Dev Indicator: Formula, Settings and How to Read It
Std Dev plots the standard deviation of closing prices over a rolling window, in the instrument's own price units. It is the raw dispersion term that Bollinger Bands multiply and add to their moving average.
Senzoukria · Indicators · Updated September 2026
Std Dev ships with the Senzoukria desktop app, in the Volatility group of the indicator catalogue. It is drawn in its own panel below the chart.
What Std Dev measures
The calculation uses the population standard deviation, dividing by N, the same convention as the Bollinger family here; multiplying this line by a band multiplier reproduces those bands' half-width exactly. The default window is 20 closes. It measures how far closes sit from their own mean over the window and nothing else — not the high-low range, not the gap between bars. Until the window holds N closes, nothing is plotted.
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:
Écart-type fenêtré du close : σ de POPULATION (÷N — même convention que les Bollinger de la famille, dont c'est le σ « nu »). Défaut N=20. Warm-up → null.
How to read it
- The vertical scale is in price units, so the level is specific to the instrument and cannot be compared with another contract without normalising.
- A rising line means recent closes are spreading further from their average; a falling one means they are clustering.
- There is no threshold that means anything on its own; what matters is where the line sits relative to the levels it held earlier on the same chart.
- Because only closes enter the calculation, a bar with a wide high-to-low span that closes near the mean barely moves this line — True Range is the measure that captures that span.
- The line is direction-blind: a steady advance and a steady decline of the same pace produce the same dispersion.
Parameters and defaults
Period defaults to 20 and accepts 2 to 200. Short windows track bursts of movement and fall back quickly once they pass; long windows describe the prevailing regime and respond slowly. Changing the period alters the shape of the line but not the divisor convention, which stays population throughout.
| Parameter | Type | Default | Range |
|---|---|---|---|
| Period | number | 20 | 2 – 200 |
What it does not show
Using closes only makes the measure blind to intrabar excursion and to gaps between bars, so a violent session that ends near where it started can look calm. Every close in the window carries equal weight and then leaves abruptly, which produces steps unrelated to the current bar. Nothing about who traded enters it: only where the closes landed. Where a market is thin enough that closes repeat, the line collapses toward zero because no print moved the close, which is an absence of activity and not a measured calm.
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
- True Range — Volatility
- Squeeze — Volatility
- Chaikin Volatility — Volatility
- Realized Vol — Volatility
- Skewness — Volatility
- Kurtosis — Volatility
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 does standard deviation measure on a price chart?
- It measures how widely recent closing prices are scattered around their own average over a fixed number of bars, expressed in price units. A larger value means closes have been landing further from the mean; it says nothing about which direction they moved.
- Is this the same standard deviation Bollinger Bands use?
- Yes. This indicator plots the population standard deviation, the same divisor convention as the Bollinger Bands in this catalogue, so the band half-width is simply this line multiplied by the band setting. Plotting it separately shows the dispersion term on its own, without the moving average underneath.
- Should I use standard deviation or ATR?
- They measure different things. Standard deviation describes the scatter of closes around their mean and ignores what happened inside each bar; ATR averages the full bar range including the gap to the previous close. For sizing a stop, the bar range is usually the more relevant quantity.