This study attempts to investigate the impacts of the disclosure of pre-IPO M&Ainformation in the prospectus on issuers' (1) IPO underpricing (i.e., the IPO first-dayreturn) and (2) long-run performance. I will divide pre-IPO acquirers into two groups:high and low disclosure degrees of their M&A information released in the prospectus(set as a dummy). I then use this information dummy and underwriters' reputation toexamine their impacts on IPO underpricing in order to test whether informationasymmetry or underwriters' allocation consideration affects the determination of offerprice. Further, I argue that pre-IPO acquirers are likely to underperform in the long run,since investors may fail to discern the quality of their M&As and extrapolate the rapidgrowth from M&As to the future. Hence, they would tend to be overoptimistic aboutthese companies. This situation is possibly more serious for companies that discloselittle information on their pre-IPO M&A activities in the prospectus.本文試圖調查美國企業在公開說明書中所揭露的上市櫃前併購資訊與公司(1) 上市櫃折價 (i.e., 第一天的報酬率) 及(2) 長期績效 (三十六個月之買進持有異常報酬率) 之關聯性；本文將公開說明書的併購活動資訊分為揭露程度高、低兩組 (虛擬變數)，利用此虛擬變數與承銷商聲譽來檢驗與上市櫃折價之關係，以便測試資訊不對稱及承銷商配售考量是否影響承銷價之決定。其次，本文認為，上市櫃前從事併購之公司長期表現可能較差，因為投資人無法辨認其併購活動的品質，將併購的成長推展到未來，因而對此種公司過於樂觀，這種情況對揭露程度較低的公司會更嚴重
