Gold is different. It is not really produced in any significant amount. The Gold that is being bought and sold on the commodities market already exists for the most part. Thats one of the major reasons that it is an economic indicator of sorts. The chances of a large amount of "new" gold hitting the market and lowering the price is almost zero. Wheat on the other hand, is a commodity that can fluctuate with the weather, amount of land in production, and emerging markets. Its also regulated. Example: The goverment will pay farmers to reduce the amount they grow at times, in an effort to keep the meager profit margin intact following a banner year. Wheat farmers also post losses alot of the time. Oil never has a loss. Oranges are oranges. People don't have to have them so its a self regulating commodity. Good years followed by bad years. They are also not a world wide commodity like oil or wheat.