초록
The purposes of this study is to verify whether insider trader get the excess return using inside information. For this we divide inside traders into four groups according to their ownership: maximum shareholder, main shareholders, 5% shareholders and executives. Also we categorize inside traders into three groups: personal investor, foreign investor and institutional investors. After insiders trade their stock, excess return is reported for 20days and the size of excess return of executives and institutional investor is larger than that of other groups. It means more strict monitoring system is needed in the domestic stock market.