The stock market has brushed off President Donald Trump’s latest volley of tariffs, but a comment he made Tuesday has jolted the market for copper, the base metal with a wide variety of applications, including in homes, cars, devices, the power grid and data centers.

The price of U.S. copper futures hit a record high after Trump told reporters at the White House that a 50% tariff on the metal was imminent. Later that day, Commerce Secretary Howard Lutnick said on CNBC that the copper tariff would come into effect in late July or early August.

The tariff rate was higher than many analysts were anticipating. This was reflected in a surge in price for copper in New York, far above the price for contracts traded in London, a global hub, suggesting that American importers are set to pay more for shipments of the metal in the months ahead. U.S. prices have detached from global averages in recent months, as American buyers front-loaded purchases to get ahead of potential tariffs.

The Trump administration began an inquiry into copper in February, investigating whether foreign production and imports of the metal posed risks to America’s economic and national security. Similar investigations have already resulted in tariffs on steel, aluminum and cars. Other inquiries are underway for pharmaceuticals, semiconductors and lumber, among other products. Sector-specific tariffs are separate from the “reciprocal” tariffs Trump has imposed at the country level, set for Aug. 1.

The United States produces a lot of copper, but still imports roughly 40% of what it consumes, primarily from Chile. Demand for copper tends to persist in the face of swings, so “producers may pass most of the tariff burden onto U.S. consumers,” analysts at the bank BTG Pactual wrote in a note. “This suggests that the proposed measure is more likely to translate into higher consumer and producer prices in the U.S., with a consequent negative impact on economic output.”

To shore up supplies of the metal, beginning in 2022 the Biden administration and the European Union put nearly $1 billion into an enormous infrastructure project in copper-rich Africa, where China has a huge presence in the sector.

In the United States, spikes in copper prices often lead to increased crime as scrap-metal thieves raid streetlights, train yards and plumbing lines to capitalize on demand.