What does backtesting measure in financial models?

Backtesting is a crucial process in the evaluation of financial models, particularly in quantitative finance and investment strategy development. It involves applying a model to historical data to assess how it would have performed in the past. This historical performance analysis helps to gauge the model's effectiveness and reliability under various market conditions.

By using historical data, backtesting allows analysts to identify strengths, weaknesses, and potential adjustments to a model before it is used in real-time trading. The results can give insights into parameters such as returns, volatility, risk metrics, and the potential for drawdowns, which are vital for making informed decisions.

The choice that highlights how a model would have performed with historical data accurately captures the essence of backtesting, making it the correct answer. This process is essential for validating strategies before deploying them in live markets. Understanding past performance does not guarantee future results, but it provides a foundation for evaluating model robustness.