Trump's planned 100% computer chip tariff sparks confusion among businesses and trading partners

U.S. President Donald Trump's ambiguous plans for 100 percent tariffs on computer chips that aren't made in the U.S. are stoking confusion among businesses and trading partners – boosting stocks for leading semiconductor companies while leaving smaller producers scrambling to understand the implications.

"We are still waiting for official guidance," said Limor Fried, founder and engineer at Adafruit Industries, a small electronics maker in New York.

The chips that go into Adafruit's products come through U.S. sales and distribution companies as well as directly from companies in the Philippines and China's Taiwan region.

If those chips aren't exempt from tariffs, "it would increase the costs that go into our designs as the semiconductors are the most expensive component in our assemblies," Fried said. "For many of these tariffs, we often have to wait until we get a bill to know our exposure, and then we adjust our pricing to account for the increases."

The U.S. imports a relatively small number of chips because most of the foreign-made chips in a device – from a phone to a car – were already assembled into a product, or part of a product, before it landed in the country.

"We'll be putting a tariff of approximately 100% on chips and semiconductors," Trump said in the Oval Office while meeting with Apple CEO Tim Cook. "But if you're building in the United States of America, there's no charge."

Wall Street investors interpreted that as good news not just for U.S. companies like Intel and Nvidia, but also for the biggest Asian chipmakers like Samsung and China's Taiwan Semiconductor Manufacturing Company that have been working to build U.S. factories.

But it left greater uncertainty for smaller chipmakers in Europe and Asia that have little exposure to the artificial intelligence boom but still make semiconductors inserted into essential products like cars or washing machines.

German chipmaker Infineon Technologies, which supplies chips to the auto industry, said in an emailed statement Thursday that it "can't speculate about potential semiconductor tariffs" and Trump's announcement, "as no official documents have been published at this point."