The understanding of co-movements, dependence, and influence between variables of interest is key in many applications. Broadly speaking such understanding can lead to better predictions and decision making in many settings. We propose Quantile Graphical Models (QGMs) to characterize prediction...

Pricing of a CDO base tranche is considered when copula is comonotone and approximations are derived for the base tranche expected loss, obtained with a one-factor Gaussian copula model, when correlations are sufficiently close to 100%. Numerical examples are provided showing that a two-term...

We develop an efficient Monte Carlo simulation-based methodology for value at risk (VaR) and sensitivity analysis of mortgage-backed securities (MBS) that employs an importance sampling technique developed for quadratic VaR models. Our approach, whose validity is derived from a fundamental...

Correlated defaults and systemic risk are clearly priced in credit portfolio securities such as CDOs or index CDSs. In this paper we study an extensive CDX data set for evidence whether correlated defaults are also present in the underlying CDS market. We develop a cash flow based top-down...

The stability of the financial system is associated with systemic risk factors such as the concurrent default of numerous small obligors. Hence, it is of utmost importance to study the mutual dependence of losses for different creditors in the case of large, overlapping credit portfolios. We...