Intraday Timing of Management Forecasts:Are Disclosures after Trading Hours Effective?

This study examines the behavior of firms with respect to the systematic intraday timing of the release of management forecasts. In particular, this study tests the hypothesis that good news is more likely to be released when the security markets are open, while bad news appears more frequently after the close of trading. According to analysis of 677 Korean cases on management forecasts from November 2002 to 2007, the results support the good news “during” and the bad news “after” hypothesis, similar to the case of earnings announcements. This study also performs an information content analysis using daily stock price data to examine how differences in the timing of disclosures affects the magnitude of the response of stock price and the speed of price adjustment. The results suggest that the information disclosed after trading hours is reflected in the opening price of the following trading day. In addition, the magnitude of the response of stock prices to the disclosure of forecast information after trading hours is not significantly different from the magnitude of responses during trading hours. This indicates that managerial actions of disclosing bad news after trading hours in order to mitigate the effects on stock prices are not effective.