기업 내부자의 군집거래와 주가성과

This study examines the stock return performance of clustered insider trading (insider herding). We analyze the short-term and long-run stock price performance of insider herding and investigate relative informational advantages among firm insider levels. Our major findings are as follows. First, we find that clustered insider purchases (sales) lead to higher (lower) abnormal stock returns both in the short-term and in the long-term period. Second, we find that insider herding which includes the largest shareholder group shows different stock return performance. Lastly, we find insider herding at each insider hierarchy level shows consistent and robust results only at the largest shareholder group. Overall, compared to non-insider herding, insider herding results in abnormal returns both in the short and in long-term periods. This suggests that insider herding contains robust private information on firm value. Especially, we find the clear relation between insider herding and stock performance at the largest shareholder group. Our results provide empirical evidence that firm insiders have different private information and largest shareholders have superior information among insider hierarchy levels.