ATR — Average True Range

Overview

Average True Range (ATR), introduced by J. Welles Wilder in 1978, measures market volatility — specifically, the typical price range an instrument moves over a period. Unlike directional indicators, ATR doesn’t tell you which way the market is going; it tells you how much it’s moving.

The ATR is the cornerstone of volatility-aware risk management. If your position sizing, stop-loss distance and profit targets don’t account for current volatility, you’re leaving consistency on the table.

Formula

True Range = max of:
   (1) High - Low
   (2) |High - Previous Close|
   (3) |Low - Previous Close|

ATR = N-period moving average of True Range
Default N = 14

The three TR cases capture not only the candle’s own range but also any overnight gap. ATR then averages this true range over N periods (Wilder used a smoothed variant; most charts now use simple or exponential averaging).

Default Settings

• Period: 14 (Wilder’s original)
• Smoothing: Wilder’s smoothing (or SMA / EMA depending on platform)

Shorter periods (5–7) react faster to volatility changes; longer periods (20+) smooth out noise.

How to Use It

1. Stop-Loss Placement

The most common and important use:

• Multiply ATR by a factor (typically 1.5 to 3) and place your stop that distance away from entry
• This ensures your stop is statistically beyond normal market noise — not too tight to be wicked out by random oscillation

Example: ATR(14) on EUR/USD = 40 pips. Using 2×ATR stop = 80 pip stop-loss.

2. Position Sizing

For consistent risk across different instruments and volatility regimes:

Position Size = (% Risk × Capital) / (ATR × Stop Multiplier)

This automatically reduces position size when volatility expands and increases it when volatility contracts.

3. Take-Profit Targeting

Set profit targets in ATR multiples (e.g., 2×ATR risk / 4×ATR reward = 1:2 R:R). Volatility-normalised targets are more robust than fixed pip / dollar amounts across different markets.

4. Volatility Regime Detection

Compare current ATR to its long-term average:

• ATR rising — volatility expanding (often during trends or news)
• ATR falling — volatility contracting (often before breakouts)

5. Chandelier Exit (Trailing Stop)

A popular trailing stop variant:

Long  trail stop = Highest High - (ATR × multiplier)
Short trail stop = Lowest Low + (ATR × multiplier)

Multiplier typically 2.5 or 3. Locks in profit while giving the trade room to breathe.

Strengths

• Universal — works on every asset, every timeframe
• Foundation of professional risk management
• Adapts automatically to changing market conditions
• Reduces the need for arbitrary stop-loss / position size decisions

Weaknesses & Common Mistakes

• Not directional — doesn’t indicate trend or reversal; combines with directional indicators only
• Spikes after news — news events temporarily inflate ATR; brief readings may not reflect typical volatility
• Too tight a multiplier — 1×ATR stops get hit constantly; 2–3× is more realistic
• Using fixed pip / dollar stops across different instruments — ignores that asset volatilities vary by orders of magnitude

Best Combinations

• ATR + Donchian Channels — the classic Turtle Trader system: enter on N-day high, exit on N×ATR trail
• ATR + Trend Indicator (MACD, EMA) — trend filter decides direction, ATR decides size and stops
• ATR + Support/Resistance — place stop ATR-distance beyond key levels for noise protection

Practical Example

Account: €10,000. Risk: 1 % per trade (€100). Setup on Gold (XAU/USD), ATR(14) = €10/oz. Stop: 2×ATR = €20. Position size = €100 / €20 = 5 oz. Take profit at 4×ATR = €40 from entry → potential profit €200 (2R). The same approach on EUR/USD with much smaller ATR would automatically scale to a larger position size.

Bottom Line

If you only ever add one volatility-based tool to your trading, make it ATR. It’s not glamorous, but it’s the single most important indicator for sustainable risk management.