I’ve noticed a commodity I trade shows backwardation in the far forward contracts when there are no trades actually occurring. The spot price can rise some days and the far forward contracts may all drop. I understand that the mid range contracts may be dropping that day, but how does Nymex determine that the close of the far future contracts also fell when there were no trades? Some days it appears they even place the close price below the actual bid price. Any idea how they determine that could possibly be the case?