Another oddity is that the chinese markets dropped 8-9% today, but the rest of asia didn't. And the US market futures are actually pointing up pretty strongly.
China's markets have been closed for the lunar new year and then some (extended lunar new year because of the virus).
As a result, they haven't had a chance to react until today, and of course, the Chinese economy is where the biggest
impact is right now. Many companies hit their daily maximum drop and were frozen from further trading until
tomorrow (or, well, today really. I'm pretty sure the markets are open already on that side of the world) and will
probably drop further.
American markets sold off hard on Friday, today was a "bounce", people buying stocks that they believe were
hit too hard by Friday's selling. America is also much less affected - America is cut off from travel to China, while
China is cut off from the world.
In any case, the American exchanges are down for the year, and have been falling since the 17th with coronavirus
fears being a large reason for that. Even so stocks will probably be up and down through the week and sell off hard
again on Friday -- short term traders don't want to risk being caught holding too many shares in case bad news breaks
over the weekend.
Both markets are behaving reasonably for their situation, and both are pricing in coronavirus fears.