Investors not only hold losing stocks too long but also continue buying losing stocks in order to turn the tables around. Referring to the relevant disposition effect studies and escalating commitment literature, this study suggests a conceptual model in which specifies the relationships among psychological factors, escalating commitment, and investment performance. Psychological factors adopted consists of mental accounting, regret avoidance and overconfidence. Quantitative data is obtained by questionnaires, and an effective sample of 760 responses is used to execute the estimation procedure by a structural equation model (SEM) approach. Results reveal that mental accounting and regret avoidance have a statistically significant effect on escalating commitment, respectively. Escalating commitment has a significantly negative effect on investment performance, but the reverse effect is significantly positive. Since the negative effect of escalating commitment on investment performance, financial institu tions are advised to market the products that can help investors mitigate their behavior of escalating commitment.