Insider Herding and Stock Price Performance

Lim, Byungkwon; Park, Soonhong

doi:2018.47.6.893

Korean J Financ Stud > Volume 47(6); 2018 > Article

Korean Journal of Financial Studies 2018;47(6):893-923.
DOI: https://doi.org/10.26845/KJFS.2018.12.47.6.893 Published online December 31, 2018.

Insider Herding and Stock Price Performance

Byungkwon Lim, Soonhong Park

기업 내부자의 군집거래와 주가성과

임병권, 박순홍

¹한국주택금융공사
²충남대학교

Abstract

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.

Key Words: 내부자거래,군집거래,최대주주,단·장기성과,사적정보,Insider Trading,Herding,Largest Shareholders,Short and Long-run Return Performance,Private Information