2008年金融海嘯肆虐全球,造成股市重挫,投資人恐慌。於此時期發現到台灣股市散戶投資人情緒會影響報酬率及有處置效果的現象存在,其原因可能是過度自信間接的影響。而人在經歷過不好的經驗時,在往後碰到相同情況會勾起回憶,這也就像散戶投資人在歷經金融海嘯的重大虧損,爾後碰到類似的狀況時會勾起其經驗,將過去的經驗套入現在的狀況。故本研究以過度自信係數模型探討金融海嘯前後台灣股市散戶投資人是否存有過度自信及其差異,並且將市值比重不同之個股加以探討。本研究結果發現,就整體大盤而言,台灣股市散戶投資人於金融海嘯前後皆存在過度自信的現象;於市值比重不同的公司時,相較於市值大的公司,台灣股市散戶投資人對於市值小的公司過度自信現象更為明顯。此外,還發現到市場走勢會影響散戶投資人的過度自信程度,於牛市過度自信現象顯著大於熊市。依不同報酬率區間區分時,研究結果顯示當上週報酬率愈高,過度自信程度就愈大。最後,三期間比較得知人在經歷過金融海嘯後,會出現經驗效應的現象。
The financial tsunami had ravaged the world in 2008, making the stock market tumbled and investors panic. During the financial tsunami, the sentiment will affect the rate of return and there existed disposition effect, which may cause by the indirect effect of overconfidence. In addition, after people have undergone bad experiences, their memories will be recollected when they encounter the same situation in the future. So after individual investors experienced substantial losses in the financial tsunami, if they meet a similar situation later, they will recollect their memory and miss interpret current situation. Therefore, this study employed an overconfidence model to investigate the overconfidence effect of Taiwan stock market and compare firms with different market value as well. Our empirical result shows that Taiwan stock market do exist overconfidence effect, both before and after the financial tsunami. For the comparison of different market value, the low market value firms show relatively overconfident than the high market firms. Moreover, the investors have more overconfident during the bull market than the bear one for all of the firms with different market value. In addition, the investors show higher overconfident when the rate of return of last week is higher. Finally, by compare these three periods, it shows the investors have the experience effect after experienced the financial tsunami.