Through extending a standard Grossman and Stiglitz (1980) noisy rational expectations economy by a heterogeneous signal structure with signal-specific differences in uncertainty, we show that price momentum as well as reversal are not intrinsically at odds with rational behavior. Differences in...

This paper finds that the majority of stock price movements remain unexplained after controlling for both public and private information. This suggests that economists' inability to explain asset price movements is the result of either noise or naive asset pricing models.

α (“Alpha”) has symbolic importance on the investments side of finance. That is, a fundamental pillar of modern finance theory is the risk-return relation, and traditionally alpha is taken to represent the degree of “mispricing” in asset returns. But, such an interpretation is not...

The quality of information in financial asset markets is often hard to estimate. This paper analyzes information transmission in asset markets when agents treat information of unknown quality as ambiguous. We consider a market with risk-averse informed investors, risk-neutral competitive...