Backtest

Updated 2026-09-20

Definition

A simulation of a strategy on historical data to estimate how it would have behaved.

Why it matters

It should be done with rules written beforehand, costs included and on a large sample; its enemies are look-ahead, overfitting and small samples. It doesn't guarantee future results.

Practical example

100 trades tested on a year of EUR/USD with +0.2R expectancy after costs.

Learn more

Course lesson: Backtesting and validation: verifying a strategy without telling yourself stories

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Full glossary

Educational content, not financial advice. Trading involves risk.