In the 1840s, the ad hoc trading of physical lots of wheat, corn, rye, oats and hay on a street corner in Chicago eventually became transaction-based on standardized terms. That development allowed traders to buy and sell physical quantities of grain for delivery at specified times in the future rather than only for spot delivery. This then evolved into a formal futures market by the late 1860s under the auspices of the Chicago Board of Trade. The ability to buy/sell grain for future delivery and avoid the obligation to make or take actual delivery through opposite transactions effectively allowed traders to make bets on what prices would be at specified times in the future without ever owning the physical supplies that attracted speculator...