- 學位論文
低庫藏股執行比率公司之股價長短期績效評估
The short- and long-term performance of stock repurchases with low execution rate
摘要
近年來，庫藏股制度之施行，已成為公司護盤及維護股價的重要工具之一。依據我國《上市上櫃公司買回本公司股份辦法》第5條規定，公司買回自家股份，應於董事會決議之即日起算二日內公告，並向金融監督管理委員會申報之，並於申報之日起二個月的時間內執行完畢，且在買回期間屆滿或是執行完畢後五日內向該會申報並公告執行情形。由於目前法令對公司實際執行庫藏股的情形，並未作出相關罰則及規範，導致許多的公司藉由實施庫藏股的名義，實際上卻是行口水護盤之實，損害了投資人權益以及公司的信譽。 因此，本研究採用事件研究法，檢視自2008年至2015年間，國內上市、櫃公司於宣告庫藏股買回後對其公司股價變動之情形進行探討，並且針對執行率未達10%的公司進行深入追蹤研究，且與執行率100%之公司進行比較與分析差異，進一步探討其庫藏股買回之股價長、短期績效表現。 實證結果顯示，公司在宣告實施庫藏股之前，股價常會有超跌之狀況，進而使得該公司股票於買回後，大部分皆存在正向的短期宣告效果。另就長期而言，實施庫藏股的公司，在長期的超額報酬較大盤指數報酬亦表現出正向顯著之情形，故存在著庫藏股宣告之長期效果。另外，執行率未達10%之公司累積異常報酬相較執行率100%之公司來得高，故研判該期間公司之宣示效果較為強烈。
並列摘要
In recent years, stock repurchase has become an important tool for companies to buoy falling stock prices. According to Article 5 of ‘Regulations Governing Share Repurchase by Exchange-Listed and OTC-Listed Companies’, a company shall register its share repurchase with the Securities and Futures Bureau, Financial Supervisory Commission after the approval of its Board, shall complete the repurchase within 2 months after the declaration date, and shall declare and announce the repurchase five days after the due date or the completion of the repurchase. The fact the current laws have yet provide clear relevant regulations on the repurchase of treasury stocks has led to a slew of companies making hollow promises to lift their stock prices under the pretext of repurchasing treasury stocks, thereby tarnishing their reputations and infringing investors’ rights. This thesis examines the fluctuations of stock prices of TSE-listed and OTC-listed companies after their announcement of repurchase of treasury stocks from 2008 to 2015. Meanwhile, this study conducts detailed investigations into companies with lower-than-10% execution rates, and compares them with companies boasting a 100% execution rate to further discuss their long- and short-term stock performances. The empirical results suggest that prior to their repurchase of treasury stocks, the researched companies’ stock prices would abnormally tumble, setting the scene for a short period of rebound after the stocks were bought back. Also, over the long term, the excess returns of domestic companies that repurchased treasury stocks also correlates with the returns of TAIEX, warranting the long-term effects of the announcement on the repurchase of treasury stocks. Moreover, the accumulated abnormal returns of companies with lower-than-10% execution rates are higher than that of those with 100% execution rate, which would be attributed to the former’s relatively strong announcement effects during the period.