Chicago corn and soybean prices fell due to increased harvests in the US and ample global supplies. Wheat futures rose after concerns about production in Argentina. The US Department of Agriculture reported that corn and soybean harvests were slightly above their five-year averages and commodities brokerage StoneX raised its estimates for US corn and soybean production. Meanwhile, Russia reached a record grain export in September, facing competition from the European Union, Ukraine, and Argentina. Russia saw increased grain exports to countries like Egypt, Turkey, Iran, and Vietnam.