首次公開發行公司併購對長期績效之影響

Abstract

本論文探討首次公開發行（Initial Public Offerings, IPOs）後的股票價格是否受到發行後短期內作為主併者之併購活動的影響，根據Brau et al.（2010）和Celikyurt et al.（2010），兩者之間存在高度相關。本研究選取於1995年至2005年之間在台灣證券交易所首次上市上櫃932家公司之樣本，分為研究組與對照組進行分析，並參考Brau et al.（2010）研究方法，利用買進持有法（Buy-and-Hold Abnormal Returns, BHAR）計算異常報酬法，透過最小平方迴歸分析法（Ordinary Least Square, OLS）與Fama-French三因子模型，比較併購與未併購公司之間股價長期績效的差異性。 研究發現台灣首次公開發行的股票存在有顯著性的異常報酬；然而，併購對於台灣首次公開發行股價之長期異常報酬並未呈現顯著性的影響，亦即，在台灣的股票市場中，併購並不會影響首次公開發行公司之長期股價。

This thesis examines whether the acquiring influences long-term stock prices following the initial public offering of a company. Brau et al.（2010） uses buy-and-hold abnormal return method to find there exists statistically significant relationship between acquiring and long-term stock prices of IPOs companies. To test this relationship, we choose 932 companies that IPO from 1995 to 2005 to calculate abnormal returns. Ordinary least square model and Fama-French three-factor model are used to verify the difference of long-term stock return between the companies acquiring within 1 year after IPO, and companies without acquiring within 1 year. The results show that there exist significantly abnormal returns following IPOs. However, IPOs that acquire within one years of going public do not significantly affect long-term return. That means acquiring does not influence the long-term stock return of IPOs.