Dev Tools · 16h ago
Trading System Debugging Reveals Common Backtesting Pitfalls
A developer audited a 16-year-old FX trading system with 7,641 trades, finding a 73.5% win rate but net losses. The diagnostic revealed two bugs: misapplied transaction costs and a reward-risk ratio that made losses inevitable. A Spearman rank correlation test showed the parameter surface was pure noise, meaning no optimization could help.
Meridian48 take
The article's real value is the Spearman rank diagnostic, which separates noisy markets from bad optimization—a technique applicable beyond trading to any parameter search.
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My trading system has a 73.5% win rate and loses money. Here is the diagnostic that found it. →
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