本文主要研究目的在於探討不同類型投資人的買賣行為是否因其對訊息認知的分歧而產生差異？以及不同的訊息內容是否會對投資人的買賣行為產生差異？實證結果發現：（1）多頭市場好消息宣告時，國內投資人傾向當賣方，但外資投資人卻傾向當買方；但不管多頭或空頭市場壞消息宣告時，國內投資人傾向當買方，但外資人卻傾向當賣方。（2）不管多頭或空頭市場壞消息宣告時，資訊來源較豐富的投資人傾向當賣方，但資訊來源較貧乏的投資人卻傾向當買方。（3）大部分的訊息內容，會對不同投資人的操作行為產生差異，唯獨在天災的訊息時例外。此結果顯示投資人可能會因國情習慣或對訊息所取得的質量、速度差異或對訊息認知的分歧而產生不同的投資行為；此外，容易被預期到的訊息對投資人在買賣行為上會產生差異，但不容易被預期到訊息，投資人的買賣行為就會較趨於一致。

The purpose of this study is to explore whether different information recognitions from different investors make their trading behaviors differently and whether different information contents affect investors' trading behaviors? The empirical findings indicate that, first, domestic investors tend to sell, while the foreign investors tend to buy as good news is announced in the bull market. While domestic investors incline to buy, and the foreign investors incline to sell when bad news is announced either in the bull or in the bear market. Second, investors with abundant information tend to sell and investors with scarce information tend to buy when bad news is announced either in the bull or in the bear market. Third, almost all kinds of information contents except natural disaster may cause different investors have different trading behaviors. These results imply that investors may have different trading behaviors due to national customs and habits or the quality, quantity and speed in capturing information, or the differences in information recognition. In addition, the information that is easily predicted by investors may cause different trading behaviors while the information that is not easily predicted by investors may lead to the same trading behaviors.