Trump has threatened to place a 25 percent tariff on imports from Canada and Mexico, as well as a 10 percent additional tariff on all imports from China. Energy resources from Canada will have a lower 10 percent tariff.

Musk, who last year said “things that inhibit freedom of exchange or distort the market are not good,” became $12 billion poorer Monday.

In many ways, these have been tough days for Tesla. Falling sales. Squeezed profit margins. Proposed changes in US government policy that could cost the company billions.