President Donald Trump tanked the stock of a tech company by demanding its chief executive’s resignation.

The president called on Intel CEO Lip-Bu Tan step down after Sen. Tom Cotton (R-AR) sent a letter to the chipmaker’s board of directors asking about his economic ties to China, and the company’s stock dropped 4.1 percent in premarket trading within minutes of Trump’s social media post.

“The CEO of INTEL is highly CONFLICTED and must resign, immediately,” Trump posted Thursday at 7:39 a.m. EST on Truth Social. “There is no other solution to this problem. Thank you for your attention to this problem!”

Cotton’s letter asked about investments Tan had made in China before he was tapped to be CEO of Intel, and the senator specifically asked about the CEO’s ties to the tech company Cadence Design Systems that he led for more than a decade.

“Intel is required to be a responsible steward of American taxpayer dollars and to comply with applicable security regulations,” wrote Cotton, who is chairman of the Select Committee on Intelligence. “[Tan’s associations] raise questions about Intel’s ability to fulfill these obligations.”

The chipmaker was recently awarded nearly $8 billion from the Chips and Science Act for U.S. investments, and the company promised to address Cotton’s concerns.

“Intel and Mr. Tan are deeply committed to the national security of the United States and the integrity of our role in the U.S. defense ecosystem,” the company said in a statement.