A Short History of commodity trading
There is obviously quite a disconnect between how commodity trading may have functioned thousands of years ago, and how they function today. This is why we will shortly go over the history of commodity starting in the ancient era.
Originally trading in commodity trading referred to trading commodities of equal value without any intermediaries (i.e. money). This could be grains for gold, or any trade people could think of with the available materials. Monetary exchanges would have started over 6000 years ago, around 4000 BCE. In the ancient world (Mesopotamia, Egypt), people would have traded these items directly. Monetary exchange systems began to develop soon after. In Sumer, for example, townsfolk would exchange clay tokens in exchange for, say, livestock. In tandem, they developed writing systems to record and keep track of all their exchanges. Usually, you could see the engravings of this information on clay writing tablets. You could equate these clay tablets with something like the earliest contracts.