계속적 과잉반응과 주식수익률의 관계에 관한 연구

This study investigates the relationship between continuing overreaction (CO) and future stock returns in the Korean stock market. Investors’ overconfidence and biased self-attribution explain the stock market’s underreaction and overreaction. We represent a proxy for the CO with monthly trading volumes and monthly returns and validate the predictive power of CO on stock returns in the Korean stock market. Specifically, based on CO, we form 10 equal-weighted portfolios at the end of each month and the CO strategy of buying the portfolio with the highest CO and selling the portfolio with the lowest CO is profitable. We also develop existing studies to reaffirm the impact of continuing overreaction on stock returns, with firm characteristic factors, momentum phenomena, return consistency, information discreteness, and unrealized capital gains as control variables. Furthermore, we introduce residual CO using residual returns to compare the profitability of residual momentum with residual CO strategies. The effects of CO on market states and market dynamics are also analyzed. Consequently, it is confirmed that a zero-cost investment with CO has statistically significant positive returns, which predicts future returns better than past returns.