A mutation is a significant change in the EA’s market fingerprint, flagged when the cosine or normalized L2 distance between the previous and current DNAMetrics exceeds the set thresholds—and usually means a regime shift (e.g., ATR, spikes, session dominance, or retracement behavior changed). Treat it as an early warning: inspect which metrics moved, tighten or pause execution (smaller size, wider ATR stops, higher signal threshold), and validate the new profile with a few recalculations ...