Direct answer
Average True Range (ATR) is a volatility indicator in forex that measures the average size of recent price movement. It is calculated from “true range,” which captures how wide price ranges are and how much they can change from one period to the next.
In practical terms, ATR summarizes how much the market has been moving recently. Higher ATR indicates larger average movement; lower ATR indicates smaller average movement. ATR does not tell you whether price will move up or down.
How ATR works in forex
ATR is typically computed over a fixed lookback period (for example, 14 bars), but the key concept is the averaging process.
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Compute the true range for each period True range is designed to handle gaps and discontinuities. For each period, it is commonly defined as the maximum of:
- the distance between the current high and low, and
- the distance between the current high and the previous close, and
- the distance between the current low and the previous close.
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Average true range across periods ATR is then the average of those true range values across the chosen number of periods.
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Interpretation
- ATR is expressed in price units (for instance, pips on a pip-based chart).
- Because it averages absolute movement, it reflects volatility (variation in price) rather than trend direction.
If you use ATR together with other indicators (such as a trend strength measure), you can compare “how strongly price is moving” versus “how much it is moving,” but ATR itself remains a movement-size metric.
Example checks you can verify independently
You can validate the idea of ATR without any live market data by applying the definitions to a small set of candles.
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Check 1: constant range If each period has the same high-low width and there are no big jumps versus the previous close, true range values will be similar, so ATR will stabilize.
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Check 2: sudden gap-like movement If the current high and low span is moderate but the previous close sits far outside that range, the true range will become larger because one of the gap comparisons will dominate. That increases ATR for that period.
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Check 3: timeframe dependency If you switch from one timeframe to another (for example, from 1-hour bars to 4-hour bars), the candle structure changes, so the resulting ATR values can change even for the “same” underlying market.
These checks follow directly from the true range definition and the averaging step.
Relevant limitations and risks
- Timeframe and lookback dependence: ATR depends on the chosen period length and the chart timeframe, so comparing ATR across different settings can be misleading.
- No direction information: ATR does not indicate whether price will rise or fall; it only reflects movement size.
- No certainty about the future: ATR is a backward-looking summary of recent volatility. It cannot guarantee future stability or instability.
- Data handling differences: ATR computations can differ in how smoothing is applied. Even if the concept is the same, implementation details can change the numeric results.
For independent verification, rely on the true range definition (including the prior close comparisons) and ensure the indicator settings (timeframe and lookback/smoothing method) match what you are reading on the chart.