Stock Market Today: GM Shares Fall After Trump Tweets Promise To Use Border Tax

Hours after President-elect Donald Trump lambasted General Motors (GM) on Twitter early Tuesday morning, the company’s share price dropped more than a dollar, or nearly 3 percent. The president-elect wasn't happy that the company manufactures its Chevy Cruze models in Mexico rather than domestically.

In a statement to the finance news site Benzinga, GM responded the same morning, clarifying that its Cruze sedan models were manufactured in Lordstown, Ohio, while the model's hatchback version was built in Mexico "for global markets," with "a small number sold in the U.S."

Trump's tweet reflected his plans, which mirror a June proposal from House Speaker Paul Ryan (R-Wisconsin), to levy a hefty “border adjustment tax” on companies moving operations abroad — which could be costly for the Detroit-based automaker.

This wasn’t the first time the real estate billionaire’s comments on Twitter have come before a dip in a company’s share prices.

Trump announced that he would “cancel” an order for a new Air Force One jet at the start of December, sending the Boeing Company’s (BA) shares down as much as 1 percent.

Boeing, the only U.S. plane manufacturer with the capacity to build a replacement for Air Force One, which is nearing the end of its 30-year life cycle, had already been awarded a $1.65 billion contract from the Air Force to build two new jets. The current crop of presidential jets, Pentagon officials told the Washington Post, “faces capability gaps, rising maintenance costs and parts obsolescence” due to its age.

In mid-December, his tweet characterizing the F-35 Joint Strike Fighter program, involving the construction of fighter jets for the U.S. military, as “out of control,” sent shares of Lockheed Martin Corp. (LMT), which manufactures the jets, down by more than $13 per share. That's just over 5 percent. The tweet effectively cut the company’s value by $4 billion, the Guardian reported.

Sen. Richard Blumenthal (D-Connecticut), who represents the state where the jets’ engines were manufactured by the firm Pratt & Whitney, wasn’t too pleased with the president-elect’s note.

“As a businessman about to become president, Donald Trump ought to know better,” Blumenthal wrote in an op-ed in the local Hartford Courant. “His 140-character tweet—one of a series that seem unwise and unproductive for an incoming commander-in-chief—jeopardizes jobs and national defense.”