<t>ok,the payoff is: MAX(U1 * NOK/EUR - U2 - X,0) The U2 and Strike are in Euros. 1. this implies you have U1 in NOK, U2 in EUR, and so the strike AND the notional must be in EUR. This means also your payoff formula is wrong because your currency exchange rate should be EUR/NOK as below (this reads ...