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.

I use uniquely comprehensive data on financial news events to test four predictions from an asymmetric information model of a firm's stock price. Certain investors trade on information before it becomes public; then, public news levels the playing field for other investors, increasing their...

This paper shows that in asset pricing the information environment gives rise to a systematic risk factor when the informativeness of future news events varies with their content (i.e., bad news and good news are not equally informative). The paper further shows that in such cases (cross) serial...