Why to Backtest

Summary: Do less backtesting. Research/backtesting to search for signals (that you already figured out could or should work).

4 reasons below. only #1 is performance related, and only to reach a "good enough" bar.

Backtesting is not a research tool. It belong right at the end of the process and you use it for four things - 1. Final verification of your idea 2. Sensitivity to assumptions 3. Reconciliation vs live trading 4. Non-performance stats like turnover, max net/gross exposure etc