Copper futures on the Comex surged as much as 17% after US President Donald Trump said he planned to implement a 50% tariff on imports of the metal. Trump’s comments — which came during a meeting with reporters on Tuesday — caused a record one-day spike in the New York contracts, and left them trading at an unprecedented 25% premium to equivalent futures in London. The global copper industry has been bracing for the levies since February, when Trump ordered the Commerce Department to lay out the case for imposing them on national security grounds. The plans have been met with resistance from manufacturers, who are ... (full story)