March 28th, 2007, 1:21 pm
Having read the Derman et al paper but not the others, I wonder if anyone can say if they are measuring both:the volatility of volatilityandthe realization (or sampling) volatilityI think the Derman paper (and perhaps others) only captures the first concept: that the stochastic process has a parameter which is not stable over time, and the smile is used to quantify the amount of instability.The second term says that the ex-ante volatility is the uncertainty of returns around the known and constant (ex-ante) risk free rate of Black-Scholes, while the variance swap payoff is calculated as the variance around the realized mean.We can imagine a binomial world where the price might follow the up up up etc only path. The variance swap would use a vol of 0, while the tree would say (if it could talk) that the vol was the same v it is in every other path, since in every node it always deviates by the same amount from the risk free rate.Do any papers explicitly model the second term? The true value ought to be based on the sum of the two.
Last edited by
savvysoft on March 27th, 2007, 10:00 pm, edited 1 time in total.