Pricing of CDOs based on the multivariate Wang transform

This paper extends the one-factor Gaussian copula model, the standard market model for valuing CDOs, based on the multivariate Wang transform. Unlike the existing models, our model calibrates the parameter associated with a risk adjustment for default threshold, not correlation parameter, which always exists and is unique for any market price of CDO tranche. A Student t-copula model is also considered within the same framework to describe a fat-tail distribution observed in the actual market. Through numerical experiments, it is shown that our model provides a better fit to the market data compared with the existing models.