What Average True Range (ATR) measures
True range is the greatest of the current high-low span, the distance from current high to previous close, and the distance from current low to previous close. ATR smooths that series over the chosen period.
The inclusion of the previous close allows overnight gaps to affect the measurement instead of disappearing from a simple high-low calculation.
How to read Average True Range (ATR)
Rising ATR describes expanding movement; falling ATR describes contracting movement. Neither tells you which direction price is traveling.
Compare fast and slow curves to see whether current volatility is above or below its broader baseline. A fast 9-period curve will normally respond before the 14- and 25-period curves.
AptiStockX default settings
AptiStockX displays three ATR curves with periods 14, 9, and 25, preserving the desktop-default colors, widths, and styles.
The interactive example starts with only Average True Range (ATR) enabled. It intentionally uses AptiStockX's synthetic SPY demo data, so the page teaches the charting workflow without presenting live market information.
A practical AptiStockX workflow
Inspect ATR around gaps, earnings-like jumps in the synthetic data, breakouts, and quiet consolidations. Match each change in the pane to the actual candle ranges.
Use ATR to normalize observations within one security, such as expressing a candle or stop distance in multiples of recent range, while remembering that this tutorial is educational rather than a prescribed risk rule.
Limitations and interpretation
ATR is expressed in price units, so raw readings cannot be compared fairly between a $20 stock and a $500 stock without normalization.
Historical range can change abruptly and does not cap the next move. Extreme gaps can exceed recent ATR by a wide margin.
Technical indicators summarize historical data. They do not predict outcomes, provide personalized investment advice, or replace independent research and risk management.
AptiStockX is a native desktop stock charting and analysis application for self-directed traders and researchers who want local data, native speed, and a durable workflow.