台灣證券交易市場向來是以散戶投資人為主體的金融市場，加上金管會2014 年開放現股可以當日沖銷，並且當日沖銷還可以享有交易稅減半的優惠，激起散戶投資人積極參與台股買賣交易。然而去年2019 年尾爆發COVID-19 新冠狀病毒大流行，在確診及死亡人數攀升影響下，台灣加權指數在2020 年3 月19 驟降至新低8,523 點，同年3 月證券新開戶數卻創下當年度新高158,349 戶。本文研究將期間設定在2020 年，探討台灣股市交易人是否存處分效果及過度自信，並以人口變數（性別、年齡）及交易行為變數（年度總交易次數、有無從事當沖交易）進行績效的統計分析。實證結果發現，台股散戶交易人確實存在有處分效果及過度自信現象，投資人明顯傾向於賺小錢而賠大錢，而過度自信頻繁的交易，對獲利並無助益。;Taiwan′s securities market has always been dominated by retail investors. In addition, the Financial Supervisory Commission (FSC) authorized day trading in 2014, and offered a 50% reduction in transaction tax, which has stimulated retail investors to actively participate in Taiwan stock trading. However, as the COVID-19 pandemic broke out at the end of 2019, the Taiwan weighted index dropped to a new low of 8,523 on March 19, 2020, yet the number of new securities account openings hit a new high of 158,349 in March of the same year. In this thesis, based on a sample for the year 2000, I investigate whether traders suffer from disposition effect and overconfidence, and conduct statistical analysis on the performance of demographic variables (gender and age) and trading behavior variables (total number of trades per year and whether they engage in day trading). The results reveal that retail traders indeed suffer from the disposition effect and overconfidence; investors obviously tend to make small profits but lose big ones, and frequent trading is not beneficial to profits.
