Copper rebounded as a metals selloff led by silver and gold eased and a state-backed industry group called for China to boost its strategic reserves of the crucial industrial metal. China should expand the size of the reserves and also work with major state-owned producers to boost commercial stockpiles, according to the China Nonferrous Metals Industry Association, which held an annual briefing to review trends in the sector on Tuesday. Most Read from Bloomberg Prices rose as much as 4.9% to $13,526 a ...