ATR (Average True Range)

What Is the ATR (Average True Range)?

The Average True Range (ATR) is a technical indicator developed by J. Welles Wilder Jr. in 1978 that measures the average price range of a financial instrument over a specified number of periods. The ATR is one of the most widely used volatility indicators in trading and is available on virtually every charting platform.

How the ATR Is Calculated

The ATR calculation involves two steps:

True Range (TR)

The True Range is the greatest of the following three values:

• Difference between the current high and the current low
• Absolute value of the difference between the current high and the previous close
• Absolute value of the difference between the current low and the previous close

By incorporating the previous close, the True Range captures gaps that occur between two periods. A simple high-low range would miss this information.

Smoothing into ATR

The ATR is calculated as a moving average of the True Range. The standard lookback period is 14 periods. Wilder used a specific smoothing method:

ATR = ((Previous ATR x 13) + Current True Range) / 14

This method gives more weight to past values than a simple average and produces a smoother curve.

How to Interpret the ATR

The ATR expresses the average price range in absolute price units. An ATR reading of 2.50 on a stock means the security fluctuates by an average of 2.50 units per period.

Key interpretation principles:

• Rising ATR: Volatility is increasing — price movements are getting larger
• Falling ATR: Volatility is decreasing — the market is becoming quieter
• High ATR relative to history: The market is in a high-volatility phase
• Low ATR relative to history: The market is in a low-volatility phase, and a breakout may be imminent

The ATR provides no directional information. It measures only the intensity of fluctuations, regardless of whether the market is rising or falling.

Using ATR in Trading

Stop-Loss Placement

The most common application of the ATR is volatility-adjusted stop-loss placement. Instead of using a fixed point value as a stop, the stop is set as a multiple of the ATR:

• 1x ATR: Tight stop, triggered more frequently
• 1.5–2x ATR: Standard stop, gives the trade adequate room to breathe
• 3x ATR: Wide stop for swing trades or volatile markets

This approach automatically adapts the stop to current market volatility. In quiet phases the stop tightens; in volatile phases it widens.

Position Sizing

The ATR is excellent for calculating position size. When a trader defines a fixed risk budget per trade in monetary terms, the ATR determines how many units to trade:

Position Size = Risk Budget / (ATR Multiplier x ATR)

In high-volatility phases the position automatically shrinks; in quiet phases it grows — a natural risk-control mechanism.

Trailing Stops

The Chandelier Exit is a well-known ATR-based trailing stop that sets the stop for long positions at the period high minus an ATR multiple. This stop moves up with the market but never pulls back.

Filter Function

Traders use the ATR to filter trades by volatility. During periods of extremely low ATR (consolidation), breakout strategies are preferred, while periods of high ATR may make mean-reversion approaches more attractive.

ATR Periods and Timeframes

The standard 14-period setting can be adjusted to fit different trading styles:

• Shorter periods (7–10): React faster to volatility changes, more noise
• Standard period (14): Balanced representation of current volatility
• Longer periods (20–50): Smoother depiction, showing the broader volatility trend

The ATR works across all timeframes — from 1-minute charts for day traders to weekly charts for long-term investors. The value changes according to the timeframe being analyzed.

Limitations of the ATR

There are several limitations traders should be aware of:

• No directional information: The ATR does not indicate whether the market is rising or falling
• Lagging: As a moving average, the ATR responds with a delay to sudden changes in volatility
• Not comparable across instruments: An ATR value of 5 means something different on a $20 stock versus a $500 stock — the percentage ATR (ATR / Price x 100) solves this

FAQ

What is a good ATR value?

There is no universally "good" ATR value. The ATR must always be interpreted in the context of the instrument being traded and its historical volatility level. Compare the current ATR reading against the average over recent weeks or months.

Which ATR period should I use?

The standard 14-period setting suits most use cases. Day traders may prefer shorter periods (7–10), swing traders often stick with 14, and position traders sometimes use 20 or more.

How does the ATR differ from standard deviation?

Both measure volatility but in different ways. The ATR is based on trading ranges (high-low-close) and captures gaps. Standard deviation measures the dispersion of closing prices around their mean. For practical stop placement, the ATR is often more intuitive.

Can I use the ATR across different asset classes?

Yes, the ATR works equally well for stocks, futures, forex, and cryptocurrencies. Because the value is absolute, the percentage ATR should be used when comparing different instruments.