Commodity market in Sumer between 4500 BC and 4000 BC. Sumerians first used clay tokens sealed in a clay vessel, then clay writing tablets to represent the amount—for example, the number of goats, to be delivered. These promises of time and date of delivery resemble futures contract. Early civilizations variously used pigs, rare seashells, or other items as commodity money. Since that time traders have sought ways to simplify and standardize trade contracts. Gold and silver markets evolved in classical civilizations. At first the precious metals were valued for their beauty and intrinsic worth and were associated with royalty. In time, they
Commodity market and (platinum). However, most ETCs implement a futures trading strategy, which may produce quite different results from owning the commodity. Commodity ETFs trade provide exposure to an increasing range of commodities and commodity indices, including energy, metals, softs and agriculture. Many commodity funds, such as oil roll so-called front-month futures contracts from month to month. This provides exposure to the commodity, but subjects the investor to risks involved in different prices along the "term structure", such as a high cost to roll. ETCs in China and India gained in importance due to those countries' emergence as commodities consumers and producers.