Excellent article. One of the most important points is the distinction between statistical fit and economic causality.

In changing market regimes, many quantitative models appear robust simply because they capture historical relationships that may no longer be structurally valid. Without a clear causal foundation behind variable selection, adaptive frameworks can unintentionally become highly efficient forms of overfitting.

This becomes even more relevant when incorporating macro, geopolitical, liquidity, and cross-asset signals into portfolio risk models. Interpretability and economic coherence are just as important as predictive performance.