Commodity market oil is traded through NYMEX under trading symbol HO. Purified terephthalic acid (PTA) is traded through ZCE in units of 5 tons with the trading symbol of TA. Ethanol is traded at CBOT in units of 29,000 U.S. gal under trading symbols AC (Open Auction) and ZE (Electronic). Precious metals currently traded on the commodity market include gold, platinum, palladium and silver which are sold by the troy ounce. One of the main exchanges for these precious metals is COMEX. According to the World Gold Council, investments in gold are the primary driver of industry growth. Gold prices are highly
Commodity (Marxism) of value, product-values in an open market are regulated by the average socially necessary labour time required to produce them, and price relativities of products are ultimately governed by the law of value. Commodity-trade, Marx argues, historically begins at the boundaries of separate economic communities based otherwise on a "non-commercial" form of production. Thus, producers trade in those goods of which those producers, have episodic or permanent surpluses to their own requirements, and they aim to obtain different goods with an equal value in return. Marx refers to this as "simple exchange" which implies what Frederick Engels calls "simple commodity