Mining firms power UK stocks to record high after 50% U.S. copper tariff confirmed

London-listed mining firms bounced on Thursday, shaking off recent losses to drive the U.K.’s FTSE 100 index to a record high as investors assessed the impact of 50% U.S. copper tariffs and stronger Chinese economic data.

Anglo American shares were 5% higher at midday in London, with Rio Tinto and Glencore both up 4.5% and Antofagasta up 3%.

The gains come amid turbulence in the copper market, where prices are at a record high and the premium paid by U.S. buyers over those in the rest of the world is soaring, following this week’s unexpected announcement that 50% U.S. duties will be introduced on Aug. 1 — at the top end of expectations.

The news is mixed for the mining giants, which have large operations in key U.S. copper export locations such as Chile, with uncertainty over supply and demand dynamics massively elevated. A broad price spike may be beneficial to producers in the short-term, according to Hargreaves Lansdown’s head of money and markets, Susannah Streeter. 

However, the main beneficiaries of higher U.S. copper prices are its major domestic mining companies which sell on Chicago Mercantile Exchange (CME) pricing, according to analysts, which are set to see higher realized revenues.

The U.S. imports just under half its copper, and is widely considered unlikely to be able to ramp up production enough to significantly alter that mix in the short-term, putting continued pressure on prices.

“Second is a weaker dollar, as that makes dollar-denominated commodities cheaper to buy with other currencies,” Coatsworth told CNBC. The U.S. dollar index was slightly lower Thursday, continuing its recent sensitivity to tariff updates.

Conversely, Coatsworth said that stock markets were broadly in a risk-on mood, shrugging off a slew of updates on national tariffs largely viewed as “noise and not facts.”

“Trump is throwing out numbers left, right and centre, and investors have begun to dismiss anything that isn’t set in stone… that means a shift in focus back to economic data and corporate news flow as key drivers for markets,” he said.

– CNBC’s Spencer Kimball contributed to this story