2. Exchanges are multilateral; buyers' needs may be met by a number of sellers, but the buyers and sellers do not or with each other 3. Margin is the ability to trade without having to pay cash for the full value of the trade. Someone who trades on margin the money used to buy or sell from the exchange or brokerage house. 4. OTC Exchanges for gas and electricity are commodity exchanges, such as the New York Mercantile Exchange (Nymex). Nymex handles physical and financial natural gas product as well as financial power contracts. What's missing on the power contracts? 2. Exchanges are multilateral; buyers' needs may be met by a number of sellers, but the buyers and sellers do not or with each other 3. Margin is the ability to trade without having to pay cash for the full value of the trade. Someone who trades on margin the money used to buy or sell from the exchange or brokerage house. 4. OTC Exchanges for gas and electricity are commodity exchanges, such as the New York Mercantile Exchange (Nymex). Nymex handles physical and financial natural gas product as well as financial power contracts. What's missing on the power contracts