Commodities are vital materials of generally uniform quality, without differentiating and marketable characteristics, that underpin the global economy and are traded in vast quantities across multiple markets on the basis of price. Commodities are an asset class in itself with a low correlation to stocks and bonds and come in several forms. There are soft commodities, which are grown, such as Coffee
There are hard commodities, which are mined or extracted, such as Oil
. Their price is influenced by global economic upturns and downturns, by advancements in technology and by unforeseen natural events. The oldest way to invest in commodities is through a futures contract that implies physical delivery at a predetermined date unless it is sold before it expires. Futures can be used to speculate with the intent to profit from price movements. Currency futures work the same way and are used to speculate on changing exchange rates.