This time-change accounts for the concept of stochastic volatility. Several authors use
such models to price exotic options, (Carr et
al., 2003; and Schoutens et al., 2003).
Recently, we have also shown how to use transition probabilities (Kienitz, 2008a) and
characteristic functions (Kienitz, 2008b), to compute stable Greeks for path-dependent options
with discontinuous payoff functions using Monte Carlo methods for a processes
of the form as Equation (1.3). Furthermore, analytic formulas based on the
characteristic function and the Fourier transform of the option's payoff function have been introduced by
Lewis (2001), to efficiently price the options.
Analytical pricing formulas based on the characteristic function and Fourier transform
methods are available for this class of models. This paper extends the applicability of
analytical pricing to options including forward start features. To this end, it derives the
forward characteristic functions which can be used in Fourier transform-based methods.
As examples, the paper considers the Variance Gamma (VG) model and the
Normal Inverse Gaussian (NIG) model subordinated by a Gamma-Ornstein-Uhlenbeck
process and respectively by a Cox-Ingersoll-Ross process. The analytical results obtained
are also checked by applying the Monte Carlo methods. These results can, for
instance, be applied for calibration of the forward volatility surface. |