Shanghai copper tumbles on trade deal concern.

Shanghai copper fell to its lowest in over a month on Wednesday as an expanding trade dispute between the United States and China intensified concerns over demand. The most-traded November copper contract on the Shanghai Futures Exchange fell as much as 0.8 percent to 46,520 yuan ($6,512.03) a tonne, its lowest since Sept. 4, tracking overnight declines in the London market.

It closed down 0.6 percent...