How to Know When Your Edge Has Actually Stopped Working

The question every trader eventually faces is also the one most consistently answered incorrectly. Has my edge stopped working, or am I just in a losing streak? Getting this wrong in either direction is expensive. Abandoning a sound strategy during a normal drawdown is as destructive as continuing to trade a genuinely broken one.

There is a specific asymmetry in how traders make this mistake. When a strategy stops performing, the instinct is to act. Change the rules. Adjust the parameters. Try a different timeframe. The action feels like taking control and responding intelligently to new information. In most cases it is neither. It is a behavioral response to discomfort, executed at the worst possible moment, on the basis of a sample too small to support the conclusion it appears to justify.

At the same time, the risk of the opposite error is real. Strategies do stop working. Markets evolve, structural inefficiencies get arbitraged away, participant behavior shifts, and what generated g…