A fixed stop distance, like "always use a $10 stop on gold," ignores the fact that gold's actual volatility changes dramatically week to week. Average True Range solves this by measuring the market's real recent range and letting your stop distance move with it rather than against it.
1. The actual ATR formula
True Range for a single candle is the largest of three values: the current high minus the current low, the current high minus the previous close, or the current low minus the previous close. Using the previous close in two of the three measures captures gaps that a simple high-minus-low calculation would miss. Average True Range is then the moving average of True Range over a chosen lookback period, most commonly 14 candles. If gold's daily True Range values over the past 14 sessions average $22, ATR(14) is $22.
2. Why the previous close matters
Suppose gold closes at $2,640 on Friday, then gaps up over the weekend to open Monday at $2,655 with a Monday high of $2,660 and low of $2,650. A simple high-minus-low calculation would show only a $10 range for Monday, understating the real volatility. True Range instead measures $2,660 minus $2,640 (the prior close), capturing the full $20 move including the gap, which is the more accurate reflection of the price action a stop loss actually needs to survive.
3. Turning ATR into a stop-loss formula
A widely used approach places the stop at 1.5x to 2x the current ATR(14) value away from entry. If gold's ATR(14) is currently $20 and you enter a long position at $2,630, a 1.5x ATR stop sits at $2,630 minus $30, or $2,600. A 2x ATR stop sits at $2,590. The multiplier choice depends on your strategy: scalping approaches with tighter time horizons often use 1x to 1.5x ATR, while swing positions held over several days commonly use 2x to 3x ATR to avoid getting stopped out by normal daily noise.
4. How ATR shifts between regimes
Gold's ATR(14) on the daily chart has historically sat around $12 to $18 during quiet, range-bound periods and expanded past $35 to $45 during major volatility events, such as an unexpected Fed policy shift or an acute geopolitical shock. A trader using a fixed $15 stop during a $40 ATR regime is almost certain to be stopped out by normal noise well before their trade thesis has a chance to play out; the same $15 stop during a $12 ATR regime may be unnecessarily wide relative to the market's actual movement.
5. Position sizing alongside an ATR stop
Because the stop distance changes with ATR, position size must adjust in the opposite direction to keep dollar risk constant. If you risk 1 percent of a $50,000 account ($500) and your ATR-based stop is $30 away, your position size is calculated as $500 divided by $30, before converting to the appropriate lot size for your instrument. When ATR expands to $45, the same $500 risk budget requires a proportionally smaller position, which is precisely the adjustment a fixed-stop approach fails to make automatically.
