Christoffer Ramsden presents his master's thesis Capturing nonlinearities of financial assets using interpolation methods in risk calculations Abstract This Master's Thesis studies how to perform efficient and accurate interpolation of prices for nonlinear financial assets when data is limited and data transfer expensive. Assets are priced using a separate derivatives pricing system and transferred to the risk system on a grid. Risk calculations are made using simulated scenarios and an asset price is needed for each scenario. A full pricing scheme such as Monte Carlo might need tens of thousands of paths to calculate one price. With tens of thousands of scenarios in the risk calculations this would not be applicable. Here interpolation, also in this setting referred to as re-pricing, provides a cheap and effective alternative. Several interpolation methods are empirically tested on a range of derivative securities with different properties. The analysis is also done on an aggregated level in order to get a picture of how interpolation errors effect risk numbers such as Value at Risk and Expected Shortfall for portfolios. Finally, suggestions on how to place grid points are given by implementing grid construction algorithms that produce an adaptive grid depending on the properties of the security repriced.