This study analyzes how equity mutual fund investor behavior has changed over time, and the associated impact on investor returns. First, we find that from 1991-2016 investor return-chasing behavior declined and more recently disappeared, while investor flows have become more sensitive to...

We study a dynamic mean-variance portfolio optimization problem under the reinforcement learning framework, where an entropy regularizer is introduced to induce exploration. Due to the time-inconsistency involved in a mean-variance criterion, we aim to learn an equilibrium strategy. Under an...

Households with familiarity biases tilt their portfolios toward a few risky assets. The resulting mean-variance loss from portfolio underdiversification is equivalent to only a modest reduction of about 1 percent per year in a household's portfolio return. However, once we consider also the...