A number of fundamental questions regarding the equity-index return dynamics are difficult to address due to the latent character of spot volatility. We exploit tick-by-tick option quotes to compute a novel "Corridor Implied Volatility,'' or CX, index which may serve as an observable proxy for...

We propose a novel model-free approach to obtain the joint risk-neutral distribution among several assets that is consistent with market prices of options on these assets and their weighted index. In an empirical application, we use options on the S&P 500 index and its nine industry sectors. The...