In fairness, that's also a bit of a weird flex - he's not even in office yet, and shares going up isn't a bad thing. That's a bit of a cheap shot. I'm sure there'll be plenty of things that will horrify us far more, but there's nothing anyone can really do but wait and see. And hope.
The man is an odious human being, but the dems were pretty pathetic in running with Kamala, and leaving Biden in post far too long (stopping them from running a proper selection - Gretchen Whitmer would have been a million times better). They've somewhat brought this on themselves (although there's a case to be made that Trump picked up a buoyant economy from Obama, it went south with Covid, leaving Biden to pick up a tricky ball on that. Unfortunately that's been used in the old "you were better off under Trump" tactic, which people have gone for, and it's likely as a result he would win against whoever they put up. I hope next time around they go with Whitmer).