The price of aluminum worldwide spiked in April after the Treasury Department put sanctions on Russian producer Rusal, following Trump’s announcement of 10% aluminum tariffs on every country (with exceptions eventually carved out for allies like Australia, Canada and Mexico).

Those price increases have since unwound in global markets, but U.S. customers continue to pay higher prices, as shown by the so-called Midwest Premium.

The price increase appears to line up very closely with the 10% tariffs imposed by Trump.