Three calculations often called volatility
Specify the input before comparing indicator values. TradingView documents RMA as the default ATR smoothing, with other smoothing choices available. Standard deviation requires a separate choice of series and denominator: population variance divides squared deviations by N, while sample variance divides by N − 1.
- The averaging operation differs. ATR averages nonnegative ranges; standard deviation squares centered observations before averaging and taking a square root. Equal lookback lengths do not make the outputs equivalent.
- Use the same symbol, session, price adjustments, chart interval, and completed bars. A daily ATR and a five-minute return standard deviation describe different sampling intervals.
| Measure | Input and calculation | Units and use |
|---|---|---|
| ATR | Smooth max(high − low, |high − previous close|, |low − previous close|). | Price units; scale a range-based distance. |
| Close-price standard deviation | Square root of the average squared distance of closes from their window mean. | Price units; describe dispersion around a price average. |
| Return standard deviation | Apply the same dispersion calculation to simple or log returns, with the return definition stated. | Dimensionless; display as a percentage for a specified return interval. |