RESOURCES / BACKTESTING FOUNDATION
Portfolio Backtesting Glossary
The terms used in a backtest should make the decision easier to understand, not create a barrier to using the tool.
Backtest
A calculation of how explicit portfolio rules would have behaved over a historical data window. It is evidence about the past, not a forecast.
Controlled comparison
Two or more backtests where one variable changes and the remaining portfolio rules stay fixed.
Result consistency
A measure of whether the direction and size of a finding remain similar across different start dates, nearby parameters, and new observations.