This paper investigates whether institutional investors trade profitably around the announcements of positive or negative earnings surprises. Using Korean data over the period of 2001–2010, we find that information asymmetry is larger before negative earnings surprises (earnings shock) among investors and that the trading volume decreases only before earnings shock announcements due to the severe information asymmetry. We also find that institutions sell their stocks prior to earnings shock announcements whereas individual and foreign investors do not anticipate bad news. Finally, we find that institutional trade imbalance is positively related to the post-announcement abnormal returns of negative events. This study complements and extends prior literature on informed trading around earnings announcements by documenting evidence that domestic institutions exploit their superior information around particularly earnings shock announcements.

Some Korean business groups, or chaebols, have a large stake in securities firms that issue analysts’ reports on their member companies. This structure is unique in that industrial companies and securities firms are affiliated and operate within the same group. We investigate the informational content of earnings forecasts, stock recommendations and target prices made by the chaebol-affiliated analysts, using data collected between 2000 and 2008. The chaebol analysts tend to make more optimistic earnings forecasts for the member companies. The mean EPS forecast error (5.36%) of the affiliated analysts for the same chaebol company are significantly larger than that (3.23%) of other chaebol and independent analysts. The chaebol analysts also assign better recommendations by almost one level and set target prices 2.5% higher to the member companies after controlling for company and analyst characteristics. These results are consistent with the hypothesis that chaebol analysts’ reports are biased by conflicts of interest. Stock market reactions do not differ in response to announcements of stock recommendations issued by affiliated vs. non-affiliated analysts. This suggests that capital markets do not recognize the conflicts of interest inherent in chaebol analysts’ reports.