Commodity arbitrage condition equates expected commodity prices to nominal interest rates plus storage costs. Any risk premium is normally subsumed in storage costs. Such an arbitrage restricts commodity marketing to speculative activities. This is an oversimplification of all the activities undertaken in commodity marketing. Studies dating from the 1940s have demonstrated that commodities are often stored even when their carrying costs are negative. Such an observation imply that there is more than speculation in commodity marketing. This paper attempts to incorporate the role of convenience stocks in commodity marketing. The intrinsic value of carrying convenience stocks referred to as convenience yield is incorporated in the commodity arbitrage.