US grain futures prices were lower in overnight trading, amid a world stock market sell off due to heightened worries about an escalating trade war between the world's two largest economies - the US and China. Corn was down around 6 cents, soybeans off around 6 to 7 cents and wheat down about 6 to 9 cents.

The Chinese currency, the yuan, depreciated to a new record low against the US dollar Monday, at 7.1087 to the dollar. This is leading to ideas China has thrown in the towel on any trade agreement with the US coming anytime soon. China's central bank appeared to condone the decline in its currency, saying the yuan's fall is the result of US protectionism and that the yuan remains stable. In the past, China's central bank had stepped in to boost the yuan when it reached 7 to the dollar.

President Trump announced late last week that on 1 September he will slap another 10 percent tariff on Chinese imports into the US. This is a body blow to the US grain markets, many of which up to last year had been major exporters to China.

Weather in the US Corn Belt remains mostly non-threatening to the US corn and soybean crops.

Technically, serious chart damage has been inflicted on the grains the past two weeks. This has prompted the technical-based bears and the big speculative "fund" traders to jump on the short side of the US grain futures markets.