Coming into Monday trading, Tesla stock was up 25% since the Nov. 5 election, down 22% year to date, up 17% since news that Musk was likely to leave DOGE in early April, and down 8% since a spat broke out between Trump and Musk on social media in early June.

Mr. Musk’s involvement in politics and his financial support for the president’s campaign were once seen by investors as a benefit to Tesla, fueling a steep rise in company shares after the election last year. That association has now turned into a liability. Tesla shares are down 40 percent from their peak in December.