Cross-Validation Techniques
Cross-validation is a statistical method used to estimate the skill of a model by partitioning data into multiple subsets. The model is trained on some subsets and tested on others, ensuring that every piece of data is used for both training and validation.
This process provides a more robust estimate of how the model will perform on new data compared to a simple split. In trading, time-series cross-validation is particularly important because the order of data points matters; one cannot use future data to predict the past.
By rotating the training and testing segments, researchers can ensure that their results are not dependent on a single, lucky data window. It is a powerful tool for identifying the stability of a strategy's predictive edge.
This helps in building more reliable models that are less sensitive to specific historical events.