The Regulation Fair Disclosure of 1999 (FD) intends to promote the full and fair disclosure of price information and further prevent insider trading. As a result, the public investors are expected to be empowered with more quality and relevant information. This study examines a behavioral shift in investor reaction to quarterly earnings announcements after the passage of the FD due to the expected improvement in information asymmetry. The empirical findings suggest that investors show a behavioral shift after the FD in response to biased earnings forecasts. Investors become more active in that they place a discount on optimistic earnings forecasts during the earnings announcement period. It is less obvious that they place a premium on pessimistic forecasts. Another coherent finding is that investors attempt to correct for the announcement-period mis-adjustments during the post-announcement period.