The once-mighty premium U.S. copper enjoyed over the global benchmark slid on Thursday as markets clawed back months of gains in hours of frenzied trading after President Donald Trump surprised markets with pared-back tariffs.

The president stopped short of putting a 50 percent tariff on refined copper, as he had threatened earlier this year. The market reaction was swift anyway and prices tumbled.

U.S. copper prices plunged after President Trump unveiled 50% tariffs on copper products, but not on the raw material itself. Copper prices surged to records this month after Trump said he would impos