U.S. equity mutual funds, on average, prefer realization of capital losses to capital gains. Nevertheless, a substantial fraction exhibits the disposition effect of realizing gains more readily than losses. My analysis suggests that learning effects have reduced the manifestation of the disposition effect over time, implying that academic research has influenced industry practices. When funds experience outflows and are managed by teams of portfolio managers, they are more susceptible to selling disproportionately more winners than losers. Disposition-driven behavior affects investment style, causing lower market betas and characteristics of value-oriented and contrarian styles, but has no observable effect on fund performance.

This is the first study of corporate bond mutual fund performance that examines detailed security-level holdings and returns. The new database allows us to decompose the costs and benefits of active management. In contrast to prior research on equity funds that shows evidence of stock-selection ability, we do not find evidence consistent with bond fund managers, on average, being able to select corporate bonds that outperform other bonds with similar characteristics. We find neutral to weakly positive evidence of ability to time corporate bond characteristics. Overall results show that the costs of active management on average appear larger than the benefits.