Contracts traded on international financial and commodity markets are associated with complex risk structures. In this dissertation we are concerned with two specific types of risks; market risks and credit risks. The first chapter investigates market risks in the context of the Nordic electricity market. The paper performs in- and out-of-sample backtesting of a VaR model based on GARCH volatility with NIG innovations. Furthermore, the Cornish-Fisher expansion is applied to get analytical approximations of the NIG based VaR estimates. Backtesting shows that the model is a promising alternative to the well known Gaussian GARCH. Results also show that the Cornish-Fisher approximation gives reasonable outcomes for the less extreme quantiles, e...