We develop a model to study the observability of investors' information acquisition in financial markets. Relative to observable information acquisition, unobservable information acquisition leads to more information production if and only if the ratio of the information-acquisition cost to...

We develop in this paper a novel portfolio selection framework with a feature of dual robustness in both return distribution modeling and portfolio optimization. While predicting the return distributions of the future market always represents the most compelling challenge in investment, any...