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Backtesting & Validation Checklist

Backtest Hygiene Checklist

Hygiene comes before validation. A backtest can pass an out-of-sample test and still be worthless if the underlying simulation leaks the future or ignores costs. Walk this list once when you build the harness, then re-confirm it whenever you add a new data source or feature.

12 ITEMSPublished May 26, 2026Live Content
By AI Fin Hub Research · AI Fin Hub Team
Best Next MovePlaygrounds

Execution Simulator

Estimate execution cost in closed form — square-root permanent impact, linear temporary impact, half-spread, and a latency-drift band. See the slippage a naive backtest hides.

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On This Page

Progress 12 items Pro tips FAQ

Checklist Progress

Move item by item and keep your place

Progress saves locally, so you can work through the page over multiple sessions without resetting your checklist.

0/12 complete

Checklist Sections

Work in focused batches instead of one long wall

Section 1

Phase 1: Data integrity

3 items

Section 2

Phase 2: Look-ahead and alignment

3 items

Section 3

Phase 3: Cost realism

3 items

Section 4

Phase 4: Reproducibility

3 items

Pro Tips

Small moves that make the checklist easier to finish

The single highest-yield audit is to plot the equity curve before and after costs. If the shape inverts, the strategy was trading the cost model, not the market.
Build the harness so that introducing look-ahead requires deliberate effort. Default every window to trailing-only and force any future-referencing code to be explicit and reviewed.
Reproduce the headline number from a clean checkout before you show it to anyone. A figure you cannot regenerate on demand is a figure you do not actually have.

Try These Tools

Run the numbers next

PlaygroundsCalculator

Walk-Forward Validator

Upload a returns CSV. Rolling or expanding IS/OOS windows, per-window Sharpe, walk-forward efficiency, and a concatenated OOS equity curve. Catches regime.

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CalculatorsCalculator

Backtest Overfitting Score

Upload a backtest trade log and compute Probability of Backtest Overfitting (PBO), Deflated Sharpe Ratio, and the odds your edge survives live trading.

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GeneratorsCalculator

Synthetic Market Data Generator

Generate synthetic price series — geometric Brownian motion, GARCH(1,1) with volatility clustering, regime-switching bull/bear, or copula-linked.

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FAQ

Questions people ask next

The short answers readers usually want after the first pass.

Entering a position on the same bar that generated the signal. A signal computed on a close cannot be filled at that close. The fix is to enter on the next available price, so every trade uses only information that was actually available when the order was placed.

Sources & References

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