If you look at their chart, there was a massive election bump. An investor trying to be savvy maybe would have assumed his businesses would benefit from proximity to power. Now that it's pretty clear he is thoroughly disinterested and distracted from his businesses.
Does Musk even want to be CEO anymore? He hasn't seemed to care about Tesla ever since he had to settle with the SEC. He got his massive payout that he will be unlikely to repeat. Ostensibly he is only CEO on paper because the magic affect his name had on stocks in the past.