Explanation : Since the futures price is less than the spot price, the market is in
backwardation. The convenience yield must be more than the cost of carry
to arrive at a futures price below the spot price because the futures price is
approximately equal to: spot price * (1 + r) + storage cost – convenience
yield. The cost of carry is defined as interest cost plus storage cost. When
the market is backwardation the roll yield for the long party is positive.