This paper shows theoretically and empirically that beta- and volatility-based low risk anomalies are driven by return skewness. The empirical patterns con- cisely match the predictions of our model which generates skewness of stock returns via default risk. With increasing downside risk, the...

We consider portfolio selection under nonparametric alpha-maxmin ambiguity in the neighbourhood of a reference distribution. We show strict concavity of the portfolio problem under ambiguity aversion.Implied demand functions are nondifferentiable, resemble observed bid-ask spreads, and are...