The latest generation of volatility derivatives goes beyond variance and
volatility swaps and probes our ability to price realized variance and sojourn
times along bridges for the underlying stock price process. In this paper, we
give an operator algebraic treatment of this problem based on Dyson expansions
and moment methods and discuss applications to exotic volatility derivatives.
The methods are quite flexible and allow for a specification of the underlying
process which is semi-parametric or even non-parametric, including
state-dependent local volatility, jumps, stochastic volatility and regime
switching. We find that volatility derivatives are particularly well suited to
be treated with moment methods, whereby one extrapolates the distribution of
the relevant path functionals on the basis of a few moments. We consider a
number of exotics such as variance knockouts, conditional corridor variance
swaps, gamma swaps and variance swaptions and give valuation formulas in
detail