Before risking real money on a strategy, you need evidence it has an edge. Backtesting and forward testing provide that evidence — and protect you from betting on a system that only ever existed in your imagination.
Backtesting
Backtesting applies your rules to historical price to see how they would have performed. Done honestly — same rules every time, realistic spreads, no hindsight — it tells you whether a setup has a positive expectancy worth pursuing. Done carelessly (curve-fitting to the past), it lies.
Forward testing
Forward testing (paper trading or a demo) runs the strategy on live, unfolding price without risking money. It reveals execution problems — hesitation, slippage, the gap between a clean backtest and messy real-time decisions — that history can't show.
From tested to live
Only after a strategy survives both, with rules you can actually follow, do you go live — and then with minimum size while you build a real track record. Testing converts a hopeful idea into a measured edge, which is the only kind worth trading.
Key takeaways
- Backtest honestly (realistic costs, no hindsight) to check for an edge.
- Forward test on demo to expose real-time execution problems.
- Go live only after both pass — then start with minimum size.