Validation of market commodity forward curves

Abstract: In this thesis the aim was to propose a method that could be used to validate the market commodity forward curve and analyse if the method is possible to apply. The thesis is limited to forward curves with equally spaced maturities up to one year and seasonal price patterns. The method suggested is to construct a reference curve by simulating futures prices with the seasonal cost-of-carry model and perform linear interpolation between these simulated values.   The validation method was applied to UK natural gas futures traded on the Intercontinental Exchange for every trading day in December 2013. Estimates were based on settlement prices for the period 2011- 01-01 to 2013-11-30. Resulting reference curves appeared to capture the seasonal behaviour of UK natural gas in a correct way and the shape of the curve seemed to follow the market curve. However the majority of observed time series representing the state variables did not fulfil model assumptions. Therefore the observation period was shortened to 2012-07-01-2013-11-30 but the result was only slightly improved. It was still the case that some of the state variable processes did not follow model assumptions. By performing likelihood ratio test it was found that for some state variables the speed of mean reversion could be set to zero.  The conclusion was that the proposed method is not appropriate to use for validating the market curve for the considered contracts. This is because model assumptions for state variables were not always fulfilled and some of the state variable process could be reduced to random walks. Perhaps model assumptions are fulfilled if the method is applied to another time period. However it is difficult to use a method for validation if historical data sometimes suggests that times series are not stationary and do not fulfil model assumptions. Finally the conclusion was drawn that for the chosen commodity the validation method is not applicable.