The Empirical Study of Stock Repurchase and Abnormal Return

本研究除了利用事件研究法實證2006年至2015年之間，上市公司宣告庫藏股買回對於其股價異常報酬的影響之外，更進一步地對兩種宣告目的(轉讓員工以及買回註銷)做實證分析並比較兩者異常報酬的情況。 本研究發現2006年到2015年之間宣告庫藏股買回的上市公司在宣告日前的平均異常報酬皆為顯著的負值，宣告日後產生的平均異常報酬為顯著正值，並逐漸下降。此外，本研究針對轉讓員工以及買回註銷兩種買回目的做實證研究並加以比較。結果顯示，在宣告日後，以買回註銷為宣告目的所產生的異常報酬比以轉讓員工為宣告目的所產生的異常報酬強烈。This study’s purpose is to do the event study of stock repurchase on the public traded companies from the year of 2006 to 2015 and observe the abnormal return. Furthermore, this study also does the empirical study of stock repurchase according to the two kinds of repurchase purposes (The purpose of protecting for the company reputation and shareholder’s equity and the purpose of transferring the stocks to employees), and compares each other. About the empirical results, first, there are all negative abnormal returns before the repurchase announcement. After announcement, the abnormal return is positive, and gradually declines. Second, the purpose of protecting the company reputation and shareholders has more effects on abnormal return than the purpose of transferring the stocks to the employees