I don't think the market sells off on that, not for long anyway. Let's say he wins. What are the chances he gets ANYTHING done legislatively? I'm sure he will do some EO, but those really don't have much of an impact and can easily be overturned (See: Obama legacy). Hell, now that I think about it, the market might rally knowing nothing much will change with a Warren or a Sanders as president. I think the Senate going Dem is where you will see a selloff.
If that happens, Dems are toast. Abrams will turn off a lot of centrists. People will be saying, well Biden is old, what if he dies, do we really want to have Abrams as president???? While I consider Trump the worst president in modern history, and bar to be better than him is extremely low, Abrams will be even worse. Biden/Obama (Michelle) ticket would be a dream team, that will win in landslide.
Not so sure.....Abrams is getting a lot of glazed knuckle love but she would be a deadweight anchor. If Biden wins the ticket, he needs to follow the model that all winning presidents have followed...bland vanilla VP candidate that neither harms nor overshadows you and waits for their turn to step up. Case in point...McCain picking Pailin versus Reagan with Bush, Bush with Quayle, Clinton with Gore, Obama with Biden, Trump with Pence. VP should be so boring you forget there even is a VP.