過去文獻常分別探討投資人情緒或從眾行為對證券市場的影響,本研究主要結合投資人的情緒、從眾與非從眾行為,除了檢視三者之間的關係以及對市場報酬與波動的影響外,亦觀察三者交互作用對證券市場的影響。結果發現,情緒影響從眾行為,從眾行為與非從眾行為互呈雙向因果關係。在多頭市場中投資人情緒或者在空頭市場中非從眾行為,與市場報酬有正向關係;在空頭市場中投資人情緒或者在多頭市場中非從眾行為,則與市場報酬有負向關係;從眾行為僅在空頭市場中與市場報酬呈負向關聯。投資人情緒與從眾行為增強了市場波動性,非從眾行為則緩和了市場的波動程度。此外,三者交互作用對市場報酬產生八種影響,分別代表著投資人在證券市場中的八種心理變化:懷疑、希望、樂觀、陶醉、過度自信、矛盾、悲觀與恐懼等階段,本文實證結果顯示,各個心理階段皆與市場報酬有很強的關聯性。
Previous literature used to pay more attention on investor sentiment or herding, while the paper focuses on the issue of the relationship among investor sentiment, herding and non-herding. The study also examines the impact of their interaction on stock market. It is found that investor sentiment affects herding, and herding and non-herding influence each other. Investor sentiment of bull market and non-herding of bear market have a positive relationship with market returns. Investor sentiment of bear market and non-herding of bull market have negative impact on market returns. Herding of bear market has negative influence on market returns only. Herding strengthens the market volatility, while non-herding weakens it. In addition, eight types of effects on the stock market resulted from the interaction among investor sentiment, herding and non-herding are corresponding respectively to eight psychological states of investor: suspicion, hope, optimism, euphoria, overconfidence, ambivalence, pessimism and fear. The study findings indicate that every psychological state has a significant influence on market returns.