The same reason why not testing for the virus doesn't stop its spread. Markets can spread psychological panic very quickly, but a lot of the short term behavior

The same reason why not testing for the virus doesn't stop its spread. Markets can spread psychological panic very quickly, but a lot of the short term behavior here is based on very short term bets about what other people are going to do on average. Give the market a month to integrate some information that is relevant over slightly longer timescales and we'll see where it thinks we are.