Risk design · July 26, 2026A backtest is testing two systems: the signal and the size.
Review position sizing, leverage, concentration, and combined open risk without hiding assumptions inside the headline.
Audit the sizing rule ↗Research design · July 26, 2026Stop grading a strategy on the data that taught it the answers.
Separate development from evaluation, freeze the rules, and protect reserved history from repeated tuning.
Build the protocol ↗Execution assumptions · July 26, 2026A backtest before trading costs is only a first draft.
Stress commissions, spreads, slippage, market impact, and turnover before interpreting the result.
Test the friction ↗Backtest integrity · July 26, 2026Look-ahead bias: when a backtest quietly knows the future.
Audit when data existed, when the signal became final, and which price could actually have been available for execution.
Audit the timeline ↗Sample-size guide · July 26, 2026How many trades are enough for a backtest?
There is no universal minimum. Judge the count alongside market coverage, independence, concentration, and stability.
Use the framework ↗Backtest checklist · Updated July 26, 2026How to validate a backtest before you trust the result.
Validate the specification, implementation, and evidence, then classify the result as pass, investigate, or reject.
Run the eight checks ↗Workflow guide · Updated July 26, 2026Backtesting and paper trading answer different questions.
Compare what each stage tests, which should come first, and how to diagnose disagreement without confusing simulation for live execution.
Choose the next test ↗Strategy design · Updated July 26, 2026If a rule cannot be written clearly, it cannot be tested honestly.
Six required decisions and a reusable template turn a market opinion into a strategy specification another person can reproduce.
Read the framework ↗Research discipline · July 25, 2026A losing backtest can be a successful research result.
A result that rejects a weak idea, catches a configuration error, or prevents false confidence has done useful work.
Read the lesson ↗Backtest notes · July 25, 2026One strategy. Two timeframes. Two very different warnings.
A 20/50 SMA idea produced zero daily trades in a seven-day sample and 51 noisy trades on one-minute data. The failure was the lesson.
Read the full test ↗