本研究旨在探討2000年至2013年間我國企業實施不同目的的股票購回之訊息內涵,並瞭解此宣告購回目的及其可信度對股價短期異常報酬及股票購回執行率之影響。研究結果顯示,企業實施「買回註銷」目的的股票購回訊息內涵最為強烈,且投資人並未能由前次宣告目的的可信度中獲取經驗,以對此次宣告後公司股價的反應進行修正。而在執行率部分,事前宣告「買回註銷」相對於其他的宣告動機,對執行率無法提供額外的解釋能力,反而是事後實際執行「買回註銷」及隱藏的「買回註銷」事件,才對管理者之實際執行率有顯著正向的影響,且隱藏的「買回註銷」行為較真實的「買回註銷」有過度修正股價低估的現象,此現象說明了管理者可能存有盈餘管理及內線交易的動機。
This study aims to explore the information content of the different purposes of share repurchases announcement and to examine the impact of the purpose and credibility of share repurchases announcement on short-term abnormal return and actual execution ratio in the Taiwan between 2000 and 2013. The results show that the wealth effect of “buying back and canceled” purpose is strongest than other purposes. Furthermore, investors can’t gain any experiences from the purpose credibility of prior announcement to correct stock price reaction. Regarding the execution ratio, compare to other motives, “buying back and canceled” motive announcement cannot provide additional explanations for the execution ratio. Instead, post-actual “buying back and canceled” and disguisedly “buying back and canceled” events have a significantly positive impact on the execution ratio of managers. Further, disguisedly “buying back and canceled” announcements suffer an over-correction underpricing of stock. The phenomenon indicates that there is a possibility of earning management and insider trading of mangers.