Vanessa Sternbeck Fryxell and Malin Norberg Trading correlated credit during a financial crisis Abstract The market of CDOs blossomed for several years but when the financial crisis became a fact in 2008 the market became increasingly turbulent resulting in a large decline in the trade of CDOs. Criticism has been leveled against the valuation models for CDOs, and primarily against the Gaussian copula model that for years has been the market standard pricing model. The objective of this thesis is to examine the market standard model for valuation of CDOs as well as more sophisticated models. The purpose of the evaluation of CDOs and their valuation models is to shed light on their shortcomings and thereby their role in the financial crisis. From our results, it is visible that both the market standard model and more sophisticated models give rise to mispricing in crisis times. The problem of valuation models for CDOs is the difficulties of reflecting the actual risk properly with the consequence of people taking on more risk than intended. Consequently, the models have, if not created, enhanced the magnitude of the financial crisis.