We relate time-varying aggregate ambiguity (V-VSTOXX) to individual investor trading. We use the trading records of more than 100,000 individual investors from a large German online brokerage from March 2010 to December 2015. We find that an increase in ambiguity is associated with increased...

We study portfolio diversification in an experimental decision task, where asset returns depend on a draw from an ambiguous urn. Holding other information identical and controlling for the level of ambiguity, we find that labeling assets as being familiar or from the homeland of subjects...

We experimentally test overconfidence in investment decisions by offering participants the possibility to substitute their own for alternative investment choices. Overall, 149 subjects participated in two experiments, one with just one risky asset, the other with two risky assets. Overconfidence...

Typical risk questionnaires aimed at helping advisors guide investors are deficient in five ways. First, each investor has a multitude of risk tolerances, one for each goal and its mental account. Probes for one global risk tolerance miss that multitude. Second, the links between answers to...

According to the behavioral concept of myopic loss aversion (MLA), investors are more willing to take risks if they are less frequently informed about their portfolio performance. This prediction of MLA has been confirmed in various experimental studies and the conclusion has been drawn that...

This paper develops a tractable dynamic model of competition between two risk-averse portfolio managers who attempt to outperform each other by trading in different stocks, reflecting asset specialization. We characterize explicitly the unique Nash equilibrium portfolio policies, and show that a...

Risk aversion is as prevalent as it is expensive. For financial traders this is especially true. This paper proposes a solution for alleviating the behavior using a model implied from experiments on myopic loss aversion and tests the model on retail currency traders from a large online database....

We consider an investor who faces parameter uncertainty in a continuous-time financial market. We model the investor's preference by a power utility function leading to constant relative risk aversion. We show that the loss in expected utility is large when using a simple plug-in strategy for...

The crisis of 2008 and 2009 exposed not only the shortcomings of our financial system but also the shortcomings of the tools used by financial advisors to assess and guide investors. These include risk questionnaires. Many investors who were assessed as risk tolerant in 2007 and assigned...

This paper analyzes gender differences in the disposition effect in an experiment based on Weber and Camerer (1998). The results emphasize that female investors realize less capital losses, have significantly higher disposition effects and are more loss averse than men