 According to the World Gold Council, ETFs allow investors to be exposed to the gold market without the risk of price volatility associated with gold as a physical commodity.Commodity-based money and commodity markets in a crude early form are believed to have originated 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.