(Bloomberg) — China’s metal markets are in the grip of a speculative frenzy, with trading values in Shanghai surging more than 260% from a year earlier, as traders and deep-pocketed funds pile into commodities like copper, nickel and lithium. Open interest has surged to a record across the six base metals traded in Shanghai, pointing to robust sentiment as investors bet on global supply tightness, resilient industrial demand and a more supportive interest-rate backdrop in China and the US. Heightened geop ...