Optimising vs Overfitting: The Hidden Danger in Backtesting

Two computer monitors showing stock charts: left with a clear upward trend, right with erratic, noisy movement

Backtesting is a critical tool for traders to evaluate strategies using historical data, helping identify weaknesses and refine approaches. However, distinguishing between optimisation, which enhances strategy logic, and overfitting, which skews results to past data, is essential. Traders must ensure their strategies remain robust and adaptable for live market conditions.