Except as authorized under subsection (b), no person shall offer to enter into, enter into, or confirm the execution of, any transaction for the delivery of any commodity under a standardized contract commonly known to the trade as a margin account, margin contract, leverage account, or leverage contract, or under any contract, account, arrangement, scheme, or device that the Commission determines serves the same function or functions as such a standardized contract, or is marketed or managed in substantially the same manner as such a standardized contract.