Data quality: how much do you trust your historical data?

Backtests are only as good as the data: gaps, bad ticks, wrong session times and broker-specific prices all distort results. Traders who check data quality discover their tests were testing artefacts.

What's your data routine?

• how you source and validate history
• the data problems you've found
• how they changed your results

The expectancy guide assumes clean data — worth ensuring.