The markets seem to wildly yo-yo with every piece of negative and positive news. Case in point: Zoom is currently down 10% but I’ll bet it will have rallied by the end of the day.
My point is that the market overreacts to every piece of good or bad news, then settles down as the full implications become clear. There are still a lot of unanswered questions about the vaccine, how we handle rollout, etc etc etc. That’s not really considered in immediate reactions like this, it’s all gut feeling.