民國91年初證券交易法通過私募股權規範之修訂後，在市場上掀起一陣私募股權風潮，慢慢成為企業重要的籌資管道之一，到95年為止一直呈現持續攀升的趨勢。前述眾多文獻指出，私募宣告具有正面的資訊效果，且發現各個公司特性顯著地影響折價幅度與市場反應。因此，本文首先探討資訊效果，且以資訊不對稱、代理問題以及其他觀點來探討如何對折價與股價反應產生影響。

本文針對民國91年初至96年4月，宣告私募股權融資之上市上櫃公司為樣本。經選樣後得143樣本，以事件研究法檢驗樣本公司在私募不同宣告時點市場價值的變化，接著探討折價與異常報酬率的影響因素，包含私募對象和股權結構的變化。主要之研究結果如下：一、私募定價宣告日具有顯著的資訊效果，私募價格富有資訊內涵。二、私募股數佔總股數之比例傳達了資訊搜集成本以及公司投資機會之資訊，因此比例越高，折價幅度越大，而資訊效果越好。三、資訊不對稱較嚴重的小公司其宣告的資訊效果並沒有比較強烈。四、公司管理者並無非常規交易的問題，代理問題不明顯。五、股權結構變動大帶給市場上正面的資訊效果，表示無鞏固股權地位的問題產生。

After the regulation of Private Equity Placement of the Securities and Exchange Law was approved in 2002, private equity placement has become one of the important ways of raising fund. Until now, more and more companies use this new funding manner. Many literatures had indicated that the announcement of private equity placement has positive information effect. And they also pointed out the different company characters would conduct different discount rate of offering price and different reaction of stock price. In this thesis, I would discuss how the information effect, asymmetric information, agency problem and other point of view would affect the discount rate and the reaction of stock price.

In this thesis, I took those companies which had announced private equity placement in January 2002 to April 2007 as our samples. After sifting, there were 143 company are included. Event Study was adopted to analyze the movements of stock prices in different announcing time and those effects that would influence the discount rate and abnormal return. The main results are listed below:（I）There was obviously positive abnormal return at the date of the offering price announcement. That means there is extra information contained in private equity announcement.（II）If the ratio of shares placed to the shares outstanding after the issue reflect information cost borne by private investors and investment opportunity. If the ratio was higher, the discount is larger and the information effect is better.（III）Small companies which have serious asymmetric information would not have stronger information effect.（IV）There is not managerial self-dealing problem. The agency problem is not obvious.（V）The change in firm value at announcement is positively associated with the change in ownership concentration when the level of ownership concentration is high. It means there isn’t entrenchment problem.

中文文獻
1.王馨晨，2005，公司治理結構與股權私募折價之關聯性，國立雲林科技大學會計系研究所碩士論文。
2.李協昌，2005，上市公司私募股權之資訊內涵及折價因素之探討，國立台灣大學會計學研究所碩士論文。
3.呂季蓉，2005，台灣上市上櫃公司私募之研究─論私募對象之影響，國立中山大學財務管理學系研究所碩士論文。
4.林育安，2005，私募股權之資訊內涵：上市（櫃）公司之實證研究，國立台灣大學國際企業學研究所碩士論文。
5.張文魁，2005，股權結構對私募發行公司價值影響之分析，國立政治大學財務管理研究所碩士論文。
6.陸潤生，2005，私募宣告之資訊內涵，國立政治大學會計研究所碩士論文。
7.黃正一，2002，我國證券私募制度探討-上-，法令月刊，第五十三卷，第九期，頁37-53。
8.黃正一，2002，我國證券私募制度探討-下-，法令月刊，第五十三卷，第十期，頁46-57。
9.黃怡翔，2005，企業私募後股價表現之研究，國立中山大學企業管理學系研究所碩士論文。
10.蔡明秀，2006，私募宣告會影響股東財富？以台灣上市上櫃公司為例，國立台灣科技大學財務金融研究所碩士論文。
11.魏竹君，2004，內部關係人交易與私募的長期績效表現，國立成功大學國際企業研究所碩士論文。

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