Commodities are the basic products that the world uses, that are mined (iron ,gold, oil,etc) or grown (wheat, cattle, soybeans etc). A commodity index averages together the pr
…ices of the commodities. There are several different commodity indexes. Some average only the metals. Some average only the grains. Some average all commodities. Also, they can differ by how they do the averaging. Some might give more weight to the more important commodities etc. The idea of a commodity index is that it gives you a clue to how the overall economy is doing as well as the industry the index covers. If the metals index is going up it means the mining industry is doing well and probably the overall economy is doing well too. (MORE) 
