Not going out on a limb to say Trump's already won the debates, but to dive in a bit further;
Demorats have their common advantage right, which is PROG sponsored debates prepared to favor their candidates. That's just become life as we know it. With this debate they'll go well beyond their common wicked ways, after all, it's Trump Vs Biden. What they'll do it anyone's guess. Expect Biden to be well juiced too. It's just not enough, Biden cannot win.
I've watched a few Trump rallies of late, IMO he's come of age in the game of it. With that and the skills only Trump can give to begin with, plus a remarkably deep resume - on paper Trump beats anyone.
We won't have to wait long before Trump takes over the first debate especially. Meaning expect interviewers to get their panties in a bunch often. Biden of course will exploit the situation "can't be POTUS if can't play fair inside our PROG-space". That's assuming Biden has anything left.
Some PROGS will suggest Biden won, while PROG news will test the waters with the notion, only to dry-up within the first hour or so. Then they'll treat the debate(s) like they didn't happen, in favor of racism, victim roles, and a BS "BOMBSHELL" or so saved for late Oct.
As for the stock market, declaring a winner is going to be tricky, primarily because similar POTUS debates PROG-play seeks a distinct advantage under what's never been done before, as they exploit COVID and our election process too. Wholly shit, mail-in being destroyed, all kinds of a mess they got us into, as usual. Expect either side to contend the results, however if we assume we were still normal, my DOW prediction for the following day is:
Trump wins uncontended: DOW gains 1900 first day, well over-appreciated, because I believe the market is already confident he'll win.
Biden wins uncontended: DOW loses 2200 first day, and loses another 2-3K within the first month.
Biden buries Trump. Stock market...plods on as will. Right wingers...gnash their teeth.
You've watched Trump "Nuremberg rallies"??
America wins. Trump supporters...lose.
Dude. Trump was unhinged. While Biden didn't land any significant punches, it was really only because Trump wouldn't let anyone else get a word in edgewise.
So far, despite the yell fest, people are generally agreeing Biden won. A lot of that was because Trump came off as a bullying little 8 year old.
If he was forced to stick to debate decorum and discuss actual policy, he would have been shredded. He did exactly what I expected a wuss to do in fight where he was in over his head. Play dirty.
Not a very Presidential look. Oh well, on to Round 2.