Setting stops with ATR instead of gut feeling

[Shadow Trader]

Average true range measures how far price typically moves over a period. Using it for stop placement ties the stop to the market's actual behaviour instead of a fixed pip number.

A fixed 4 pip stop might be generous on a quiet afternoon and laughably tight during the London open. An ATR-based stop adapts: if ATR on the one-minute chart is 2 pips, a stop at 1.5 times ATR sits at 3 pips, and when ATR doubles, the stop widens with it.

Position size then adjusts so that the money at risk stays constant. A wider stop means smaller size. That's the part many forget, and without it, a wider stop simply means bigger risk.

The multiplier takes testing. Too tight, and noise tags the stop. Too wide, and the reward to risk deteriorates. Many scalpers land somewhere between 1 and 2 times ATR, though the right figure depends on the entry method.

Which ATR period and multiplier have survived real testing, and do they change by pair?