A lot of businesses are cutting back because people can't go out and do what they'd normally do legally. So when governments start easing restrictions, people [stockholders] are probably more optimistic because the situation seems more tractable. It's a lot more predictable than 2008 when people were talking about the collapse of fundamental financial institutions and systems involved in monetary supply because of their underlying structural composition.
I do think there's some disconnects in interpreting the stock market, but it seems to me investors are just seeing restrictions being eased, daily COVID case counts on a downward trajectory, etc. They're reinvesting in markets they see a path of recovery in, early.
What's less certain to me is if in say, July, this all gets worse again with overrun hospitals, etc. in a second wave. Then markets might really take a nosedive.
Plus there is the expectation that once a vaccine is developed/distributed it'll be the roaring 2020s as everything recovers fully, which I largely agree with. So if you're looking at record profits less than 2 years out, makes for a pretty rosy outlook.
That of course is assuming there aren't any particularly economically devastating effects from the oil price wars/demand drop, educational lapses, hurricanes/wild fires on top of corona-virus leading to a renewed spike during evacuations, and any other manner of things that can go wrong. That's where I'm generally making the opposite bet, there's just too many unknowns and plausible disasters that can happen, and if even one of them comes true things get a lot worse quickly. But that's pure speculation/conservatism on my part.
Can't post this enough these days. TLDR is that the stock market is forward looking. It goes up or down based on whether conditions are better or worse than EXPECTED. If reality is in line with expectations then nothing happens. If it's better than expected stocks go up, if it's worse than expected stocks go down. The current shitty economy has already been priced in as far as can be known.