COMMODITY exchanges include the Chicago Board of Trade, the Chicago Mercantile Exchange, the New York Mercantile Exchange, and the Board of Trade of the City of New York. A federal agency called the Commodity Futures Trading Commission regulates the exchanges.

TRADE OR TRADING, the act or process of buying and selling; exchange of goods; commerce. Ex. wholesale trade, retail trade, domestic trade. The United States has much trade with foreign countries. ONLINE service is a business that provides access to the Internet, a global computer network, and also offers a wide range of content not available on the Internet. The foreign exchange market (currency, forex, or FX) trades currencies. It lets banks and other institutions easily buy and sell currencies. The purpose of the foreign exchange market is to help international trade and investment. A foreign exchange market helps businesses convert one currency to another. For example, it permits a U.S. business to import European goods and pay Euros, even though the business's income is in U.S. dollars.

SYSTEM, a set of things or parts forming a whole. Ex. a mountain system, a railroad system.
Title to most of the nation's gold is held by the Federal Reserve System (Wall Street Journal).
Not every system is treated in cybernetics. Cybernetics is only concerned with controlled systems (V. G. Drozin).