Modelling the Evolution of Credit Spreads using the Cox Process within the HUM Framework: A CDS Option Pricing Model

Abstract

In this paper a simulation approach for defaultable yield curves is developed within the Heath et al. (1992) framework. The default event is modelled using the Cox process where the stochastic intensity represents the credit spread. The forward credit spread volatility function is affected by the entire credit spread term structure. The paper provides the defaultable bond and CDS option price in a probability setting equipped with a subfiltration structure. The Euler-Maruyama stochastic integral approximation and the Monte Carlo method are applied to develop a numerical algorithm for pricing. Finally, the Antithetic Variables technique is used to reduce the variance of CDSO estimations.HJM model; Cox process; Monte Carlo method; bond price; CDS option