agricultural products and other raw materials (like wheat, barley, sugar, maize, cotton, cocoa, coffee, milk products, pork bellies, oil, metals, etc.) and contracts based on them. These contracts can include spot prices, forwards, futures and options on futures. Other sophisticated products may include interest rates, environmental instruments, swaps, or freight contracts. Traded commodity classes Source: International Trade Centre Energy Energy commodities include crude oil particularly West Texas Intermediate (WTI) crude oil and Brent crude oil, natural gas, heating oil, ethanol and purified terephthalic acid. Hedging is a common practice for these commodities. Crude oil and natural gas For many years, West Texas Intermediate (WTI) crude oil, a light, sweet crude oil, was the world's most-traded commodity. WTI is a grade used as a benchmark in oil pricing. It is the underlying commodity of Chicago Mercantile Exchange's oil futures contracts. WTI is often referenced in news reports on oil prices, alongside Brent Crude. WTI is lighter and sweeter than Brent and considerably lighter and sweeter than Dubai or Oman. From April through October 2012, Brent futures contracts exceeded those for WTI, the longest streak since at least 1995. Crude oil can be light or heavy. Oil was the first form of energy to be widely traded. Some commodity market speculation is directly related to the stability of certain states, e.g., Iraq, Bahrain, Iran, Venezuela and many others. Most commodities markets are not so tied to the politics of volatile regions. Oil and gasoline are traded in units of 1,000 barrels (42,000 US gallons). WTI crude oil is traded through NYMEX under trading symbol CL and through Intercontinental Exchange (ICE) under trading symbol WBS. Brent crude oil is traded in through Intercontinental Exchange under trading symbol BRN and on the CME under trading symbol BZ. Gulf Coast Gasoline is traded through NYMEX with the trading symbol of LR. Gasoline (reformulated gasoline blendstock for oxygen blending or RBOB) is traded through NYMEX via trading symbol RB. Propane is traded through NYMEX, a subsidiary of Intercontinental Exchange since early 2013, via trading symbol PN. Natural gas is traded through NYMEX in units of 10,000 million BTU with the trading symbol of NG. Heating oil is traded through NYMEX under trading symbol HO. Others 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