內部人在強制集保結束後出售持股對股價影響之研究

• Main Author: 陳淑娟
• Other Authors: 徐政義
• Format: Others
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/99423978168173869602

碩士 === 中華大學 === 經營管理研究所 === 95 === This study investigates the stock price behaviors of 36 Taiwanese IPOs around the period of lockup expires ( event I ) and around the first announcement of insider selling ( event II ) after listing. We acquire a unique dataset, Which enables us to understand whether insiders sell their shares after lockup expires or not, through the assistance of an underwriter . we find that the stock prices go down accompanied with trading volume moderately increases when the IPO lockup expires. Among 36 sample IPOs, there are 25 firms that have insider selling in the one year period after the lockup expires. The stock price obviously goes up before the first announcement of insider selling, but price significantly depreciates after the announcement, indicating that insiders in these IPOs take advantage of the " window of opportunities" to announce selling at the peak of stock price. Evidence obtained from both event I and II supports the fact that the Taiwan stock market is not efficient.