1997年亞洲金融風暴嚴重影響台灣股市，為能使上市上櫃公司遭遇特殊情況而導致股價下跌時，能有辦法傳遞出公司股價遭受嚴重低估之訊息，財政部證劵暨期貨管理委員會於2000年8月7日依證劵交易法第二十八條之二規定，訂定「上市上櫃公司買回本公司股份辦法」，使得公司能依照規定購回自家股票。
本文使用事件研究法及複迴歸分析，探討公司宣告庫藏股購回後，平均異常報酬與宣告買回目的、宣告買回次數、預計買回比率及實際買回比率之間，在不同的11個年度及不同窗期(-10~+10)與窗期(-10~+30)下，是否存在一致的關聯性，以檢視庫藏股決策與公司股價之聯繫。
實證結果顯示，預計買回比率愈高及實際買回比率愈高，對平均異常報酬呈現顯著性相關，而買回目的對平均異常報酬則呈現無顯著性相關。
The 1997 Asian Financial Crisis severely affected the Taiwan stock market. To enable listed companies conveying the message to the market that the price of their stocks was seriously below the fair level due to special conditions. The Securities and Futures Commission of the Treasury Ministry, on August 7, 2000 amended the Securities Exchange Act, Article 28-2, with the "Listed company shares repurchase regulation", allows the company to repurchase its own shares in accordance with the legislation.
This thesis applied the event study methodology and multiple regression analy-sis to explore the association among average abnormal returns, the declared purpose of repurchase, the frequency of repurchases, the ratio of declared repurchase, and the actual rate of repurchases. The period of investigation is from 2000 to 2010. The two windows chosen are (-10 to +10) and (-10 to +30). We look for consistent findings among the years and windows.
Empirical results show that the declared and actual repurchase ratio are both positively related to average abnormal returns, while the average abnormal returns and redemption purposes do not show any significant correlation.
