Commodity contract shall mean any account, agreement, or contract for the purchase or sale, primarily for speculation or investment purposes and not for use or consumption by the offeree or purchaser, of one or more commodities, whether for immediate or subsequent delivery or whether delivery is intended by the parties, and whether characterized as a cash contract, deferred shipment or deferred delivery contract, forward contract, futures contract, installment or margin contract, leverage contract, or otherwise. Any commodity contract offered or sold shall, in the absence of evidence to the contrary, be presumed to be offered or sold for speculation or investment purposes.