ATR-based position sizing is a professional approach that adapts your position size to each instrument’s actual volatility. Instead of using arbitrary stop levels, you let the market tell you where to place your stop.
How ATR Position Sizing Works
The core idea is simple:
- Measure volatility using ATR (Average True Range)
- Set stop distance as a multiple of ATR (e.g., 2x ATR)
- Calculate position size to keep dollar risk constant
This means you automatically trade fewer shares of volatile stocks and more shares of calm stocks — keeping your dollar risk identical.
The ATR Stop Loss
Stop Distance = ATR x Multiplier
Stop Loss Price = Entry Price - Stop Distance (for longs)
Multiplier Guidelines
- 1.5x ATR: Tight stop, more frequent exits, smaller losses
- 2.0x ATR: Standard, balances noise filtering with risk control
- 2.5-3.0x ATR: Wide stop, rides through more volatility
Why ATR Beats Fixed Stops
Consider two stocks, both at $100:
- Stock A: ATR = $1.50 (low volatility)
- Stock B: ATR = $5.00 (high volatility)
A fixed $3 stop on Stock A is 2x ATR (reasonable). The same $3 stop on Stock B is only 0.6x ATR — it will get hit by normal daily price movement.
ATR sizing adjusts automatically, giving Stock A a $3 stop and Stock B a $10 stop, while keeping your dollar risk the same.
How JournalPlus Helps
JournalPlus calculates ATR-based stops and position sizes automatically for every trade. It also tracks whether ATR-based stops outperform your fixed stops across your trading history — so you can see which approach actually works better for your style.
