本研究以2000年至2010年台灣證交所上市股票報酬率為樣本,檢驗當首次公開發行事件發生時,是否會對同業對手公司股價造成影響。本研究分別以「註冊新聞發佈日」、「掛牌交易首日」為事件,以事件研究法為研究方法,並以競爭效果與蔓延效果解釋首次公開發行對同業股價的影響方向。根據本研究實證結果,首次公開發行之註冊新聞發佈與掛牌交易當日,都將引起同業平均-0.17%與-0.19%之累積超額報酬。另外,本研究亦發現股市處於空頭行情時,首次公開發行將帶動同業股價上漲,造成平均0.14%的累積異常報酬。 除上述樣本外,本研究亦另外蒐集1990至2000年間電子工業與金融保險業之股價資,檢驗產業特性對首次公開發行中同業股價的影響。實證研究結果顯示,電子工業的首次公開發行將造成同業股價出現顯著為負之累積超額報酬,金融保險業的首次公開發行對同業股價的影響則不顯著。金融保險業的不顯著結果來自政府法規改變了產業特性,使得金融保險業下各子產業的競爭效果與蔓延效果作用力相互抵消所造成的現象。
This thesis attempts to examine the valuation effect on industrial rival stocks of IPOs. The sample is composed by listed stocks in Taiwan Stock Exchange, rivals of IPOs in 2000 to 2010. The event study is used to examine exist of cumulated abnormal returns (CAR). And we attempt to analysis the way rivals be affected by contagion effect and competitive effect.We find that rival stocks suffer negative return significantly. The average CARs of rivals are -0.17% and -0.19% in filing date and listing date in respect. However, rivals perform positive returns significantly when IPO in weak stock condition. To know how industry nature affecting the rivals of IPOs, we collect data of high-tech and finance in 1990 to 2000. The IPOs of high-tech industry make rivals return loss significantly. But the relation between IPOs and rivals returns is not significant in finance. It is attributed to the government intervention enhancing the competitive effect of finance. The offsetting of competitive and contagion effect turns out insignificant result.