三.最後，本研究再加入代表產業、市場趨勢及增資目的三大虛擬變數，分別探討對增資宣告效果的影響。結果發現，對各事件窗口累積異常報酬之解釋能力以（-1,0）區間最高。係數方面僅以股東權益報酬率達0.01顯著水準。 This research focuses on the impacts of different industries, market-trends and issuing purposes on seasoned equity offering’s announcement effects. In this paper we use a sample of 180 electronic companies which issued seasoned equity offerings between 1995 Jan 1 and 2004 Dec 31.We study the samples using event study methods, t-test and multiple regression. Our conclusions are:
1.We findthe abnormal returns are negative on "stockholders meeting authorized date."When we divide the sample into three groups. We find that offerings by non-optoelectronic firms, issued during bull-market and issued for non-investment purposes are associated with negative and significant cumulative abnormal returns.
2.When considering"Dilution Effect"、"Growth Opportunities" and "Insiders Trading",we find that dilution effect is negatively associated with SEO announcement’s abnormal return. We also find that growth opportunity is positively associated with SEO announcement’s abnormal return. Insiders trading, on the other hand, has no significant impact.
3.Finally,we add three dummy variables:"Industry", "Market-trend" and "SEO''s purpose" into the model. And we find that ROE is positively associated with SEO announcement''s abnormal return.