After the 1987 crash, the S&P500 index implied volatility changed from nearly flat to negatively sloped. According to Rubinstein the Black-Scholes model was not so wrong when applied to the ...
Given an implied volatility surface (on equity indexes) and a calibrated model, what is the range of error on implied volatility a trader would accept ? This obviously depends on the model used to ...
Possible Duplicate: How to derive the implied probability distribution from B-S volatilities? Let's assume a stock price S, with volatility $\sigma$ constant, no dividend, and risk free ...