Please validate my unrealized Fx P&L calculation on the commodity forward contract e.g. consider i have bought 1 MT of wheat at 300 EURO my financial currency for company is USD. I am using below formula to get attribution .
(Market Price - Commodity Price )*(Today FX Rate- Yesterday FX Rate)
The above formula is used for daily fx loss and gain on the forward position . But above failed when the market price = commodity price .