本研究利用共同基金流量衡量投資人情緒，探討投資人情緒對於共同基金績效以及基金持股超額報酬之影響，並進一步探討其相互關係。本研究之投資標的為國內上市櫃股票之開放式股票型基金為研究對象，研究期間為2000年1月至2008年12月。研究結果顯示，共同基金在短期投資人之情緒水準下，存在愚笨錢效果。我們發現高情緒的基金比低情緒的基金其在未來的績效相對較差。不論前期基金績效的高低，基金績效存在持續性現象，且高情緒的基金其未來績效皆不如低情緒的基金。此外，在基金持股的超額報酬方面，發現高情緒的股票比低情緒的股票其在未來的超額報酬相對較差，若高情緒使得股價被推動而超過了基本價值，其在未來將會出現低報酬。因此，不論前期股票報酬的高低，高情緒的股票其在未來報酬皆不如低情緒的股票。

In this study, we use mutual fund flows as a proxy of individual investor sentiment to explore whether investor sentiment affects mutual fund performance and excess return. All domestic open-end equity mutual funds from January 2000 to December 2008 were included in this study. The results show that there is dumb money effect in short horizons of investor sentiment. We found that mutual funds with lower investor sentiment exhibit higher future return than those with higher investor sentiment, no matter the funds had high or low past return. Excess return of stocks also shows the same results. Due to the high sentiment, stock price was raised over its fundamental value. So, high sentiment investor always has lower future return than low sentiment investor in the future. Therefore, we can conclude that investors' sentiment would affect their wealth. Consequently, investors should avoid emotional investment behavior.