Let me start by saying that I know nothing about the stock market.
Let me follow that up by saying that neither does anyone else.
Some of the valuation is based on economic activity. But a lot is human psychology. Hence the booms and busts.
Let me add to the speculation (again, as a know-nothing).
I think there are two other possibilities, and neither are very good to consider.
I know people who have never invested who are investing. The investing apps are booming in popularity. No one wants to miss the boat...
If you're wondering how stocks can rally while people are at home without work, it might be because people are at home without work but with a computer and a smartphone and a desire to make a quick buck.
Lowe's and Home Depot? Easy.
Local roofing company or plumping contractor? Impossible.
Maybe not yours, but enough people to make a difference. These are businesses with small margins. They can't be profitable at 75% former capacity.
Our collective foot just hammered the accelerator.
Hopefully I'm wrong.
I probably am.