A stop-loss placed a fixed number of dollars away ignores the single most important thing about a market: how much it moves. In a quiet market that stop is too far; in a volatile one it's too tight and gets clipped by normal noise.
What ATR measures
Average True Range (ATR) is the average size of a candle's range over the last 14 periods, a direct measure of current volatility. When the market is calm, ATR is small; when it's wild, ATR expands.
How LazyChart uses it
Every signal places the stop-loss 1.5× ATR from entry and the take-profit 3× ATR away. That gives a consistent 1:2 risk-to-reward ratio that automatically widens in volatile conditions and tightens in quiet ones, the stop sits beyond normal noise but no further.
Why 1:2
With a 1:2 ratio you can be wrong more often than right and still come out ahead: winning trades return twice what losing trades cost. It doesn't make a strategy profitable on its own, but it means the maths isn't working against you from the start.