01 Mar 2009, Lorenzo Bergomi, Risk magazine
To remedy some of the limitations of popular models used for equity derivatives hightlighted in previous work (Bergomi, 2004), we proposed a stochastic volatility model based on a specification of the joint dynamics of the underlying spot and its implied forward variance swap (VS) variances (Bergomi, 2005). The aim of this model was to afford better control of:
- the term structure of the volatility of volatility;
- the forward skew; and
- the correlation between spot and VS volatilities for the pricing of options such as reverse cliquets, accumulators and options on realised variance. In practice, as there were no traded instruments to hedge the volatility-of-volatility risk, the level of the corresponding parameter in our model was set to a conservative value and we concluded our article with the following statement: "It is the hope of the author that the liquidity of options on volatility and variance increases so that we will soon be able to trade the smile of the volatility of volatility!"