The once-mighty premium US copper enjoyed over the global benchmark shrank to near zero on Thursday as markets clawed back months of gains in hours of frenzied trading after President Donald Trump surprised markets with pared-back tariffs. Trump said on Wednesday the United States would impose a 50% tariff on copper pipes and wiring, but the levy fell short of the sweeping restrictions expected and left out copper input materials such as ores, concentrates and cathodes.The surprise move dragged down Us copper prices more than 18% on the Comex exchange HGc2 and unwound a large part of the premium over the London ... (full story)