Speaking at a celebratory rally in Washington, Mr. Musk twice extended his arm out with his palm facing down, drawing comparisons to the Nazi salute.

After telling the audience "thank you" for reelecting Trump, Musk appeared to grab his chest and then forcefully extended his right arm fully into the air with an outstretched straight hand while making a grunting noise. He then turned around and repeated the gesture before touching his chest again and telling the crowd, "My heart goes out to you."