• Backtesting evaluates the viability of a trading strategy or pricing model by discovering how it would perform retrospectively using historical data.

  • The underlying theory is that any strategy that has performed well in the past is likely to perform well in the future, and conversely, any strategy that has performed poorly in the past is likely to perform poorly in the future .
  • When testing an idea on historical data, it is useful to reserve a period of time for historical data for testing purposes. If successful, testing it on alternative time frames or on out-of-sample data may help confirm its potential viability.