To measure the quality of the VaR we have backtested OPAS using optimised as well as stochastically generated forex portfolios covering 9 major currencies against the US dollar. The computation was done over 391 days ranging from 01.01.1999 to 30.06.2000. The results of the calculation are presented as a ratio of the number of loss exceedences of the calculated VaR (1 Day and 2 weeks) to the number of theoretically expected exceedences plotted against the confidence level for which the VaR was computed. This measure is decribed in more detail in section entitled Performance Measures in our VaR Paper.