We provide evidence of a strong effect of the underlying stock's illiquidity on option prices by showing that the average absolute difference between historical and implied volatility increases with stock illiquidity. This pattern translates into significant excess returns of option trading...

In equity option markets, traders face margin requirements both for the options themselves and for hedging-related positions in the underlying stock market. We show that these requirements carry a significant margin premium in the cross-section of equity option returns. The sign of the margin...

The thesis studies index and equity option returns in perfect and imperfect markets to explain parts of the option mispricing puzzle. Perfect markets exist under informational efficiency, market completeness and frictionless trading. The thesis shows that an option-implied risk-adjusted approach...