At a celebratory rally after Trump’s inauguration, Musk’s White House career got off to a contentious start when he seemingly offered a straight-arm salute at the Capitol One Arena in Washington, D.C., as he excitedly told the crowd: “My heart goes out to you.”

Elon Musk exits the White House, leaving investors hopeful that he will renew focus on his companies, Tesla and SpaceX. Mr. Musk gave nearly $300 million in contributions to the U.S. presidential election campaign.