President Donald Trump said his 50% tariff on copper imports will take effect on Aug. 1, noting he made the decision after a national security assessment.

Copper futures in New York surged after US President Donald Trump said he planned to implement a 50% tariff on imports, a move that’s likely to spark massive supply-chain ripples through global metal markets.

While the cost of copper is going up for American businesses and consumers, the rest of the world is scratching its head while it enjoys a considerable discount on the price of copper.