We study the effect of an asset's volatility on the expected returns of European options written on the asset. A simple stochastic discount factor model suggests that the effect differs depending on whether variations in volatility are due to variations in systematic or idiosyncratic volatility....

From 1963 through 2015, idiosyncratic risk (IR) is high when market risk (MR) is high. We show that the positive relation between IR and MR is highly stable through time and is robust across exchanges, firm size, liquidity, and market-to-book groupings. Though stock liquidity affects the...