Vectorized vs Bar-by-Bar: Pitfalls of Both Implementations
📅 2026-08-12 · SmartQuant Academy
TL;DR: TL;DR: Vectorized backtests are fast but hide look-ahead bias and position timing issues; bar-by-bar is slower but explicit. Know which one you're using and verify with a small manual trade.
❓ FAQ
Which backtest style is better?
Bar-by-bar for correctness, vectorized for speed. Verify vectorized results against bar-by-bar on a small sample.