There's no good active trading solution here because no one knows what's going on. People occasionally make the right calls, but they also occasionally make the right calls on coin flips, too.
There's a reason for that: the only good solution is a passive one. Ignore the panic, hold, stay the course, and put more money into the stock market when it's down. The large majority of active traders do worse than the market average because of panic selling in situations just like this one.
Plus if you follow a textbook approach with some % stocks / bonds you'll end up buying when the market dips and selling when it goes up (since if stocks go up you'll have to sell a little to bring the percent back down and vice versa). So if the market swings up and down a lot you get a little extra.
There's a reason for that: the only good solution is a passive one. Ignore the panic, hold, stay the course, and put more money into the stock market when it's down. The large majority of active traders do worse than the market average because of panic selling in situations just like this one.