... a lot of people ... have no plan...
Here's a plan that works well in this situation, in case anyone is lacking a necessary plan: Buy low, sell high. Now is the buy low part.
Buy low, sell high is not a plan, it's more the motto for the plan ;-)
But talking seriously - no matter where the bottom is, on 560 or a lot lower - people should mentally plan bearish cases, too.
Or they freak out on unexpected movements.