Short selling, as compared to purchasing, faces greater risks and other potential impediments. This arbitrage asymmetry explains the negative relation between idiosyncratic volatility (IVOL) and average return. The IVOL effect is negative among overpriced stocks but positive among underpriced...

Many investors purchase stock but are reluctant or unable to sell short. Combining this arbitrage asymmetry with the arbitrage risk represented by idiosyncratic volatility (IVOL) explains the negative relation between IVOL and average return. The IVOL-return relation is negative among overpriced...

The beta anomaly — negative (positive) alpha on stocks with high (low) beta — arises from beta's positive correlation with idiosyncratic volatility (IVOL). The relation between IVOL and alpha is positive among underpriced stocks but negative and stronger among overpriced stocks (Stambaugh,...