Overall, 72 subjects invest their endowment in four risky assets. Each com-bination of assets yields the same expected return and variance of returns. Illusion of expertise prevails when one prefers nevertheless the self-selected portfolio. After being randomly assigned to groups of four...

Many tests of asset pricing models address only the pricing predictions - but these pricing predictions rest on portfolio choice predictions which seem obviously wrong. This paper suggests a new approach to asset pricing and portfolio choices, based on unobserved heterogeneity. This approach...

High sentiment predicts low market returns and high arbitrage returns. This empirical evidence has important implications for portfolio optimization. Exploiting the eigenvalue-decomposition of the mean-variance portfolio, I show that its performance is the sum of two components: a market...

We develop a new method to optimize portfolios of options in a market where European calls and puts are available with many exercise prices for each of several potentially correlated underlying assets. We identify the combination of asset-specific option payoffs that maximizes the Sharpe ratio...

As a result of the recent financial crises, equity markets have performed poorly in the last five years or so. In consequence, equity long-only strategies have generally been unattractive over this period. This motivates the investigation on whether better performance can be achieved by...

Financial product ratings are intended to summarize relevant information in a manner that assists in decision-making. Ratings, however, have the potential to be either helpful or harmful. Ratings are often assigned within categories; ratings across categories then may or may not be comparable....

We conduct a study in which subjects trade stocks in an experimental market while we measure their brain activity using functional magnetic resonance imaging. All of the subjects trade in a suboptimal way. We use the neural data to test a “realization utility” explanation for their behavior....