You probably do grasp it better than you think.
For instance; you know people have gotten laid off in record numbers. That means people aren't getting paid. People who aren't getting paid are clamping down on any expenditure possible aside from absolute necessities. That means, if you're entertainment in any way, you are likely hosed unless your specialty is direct to consumer last mile service.
Production/producers may see some growth. There may be more growth in sectors that enable remote work/telepresence. Otherwise, just about everything else will be dropping, and stimulus will likely slow the drop but not reverse it until the pandemic has run it's course sufficiently that healthcare systems are no longer overwhelmed. Most likely, other shareholders are seeing this too, and are trying to cash out, further fueling the drop in share prices across the board. The people who correctly timed the market have already gone and converted their assets to cash, which is king in deflationary periods.
The stimulus might provide some liquidity/stimulated demand, but I have the feeling a liquidity trap situation may occur where people will hold onto any injected value for dear life.
I wouldn't hold much faith in any type of securitized asset right now unless it's from a big (established) player; and Note that that isn't necessarily "good" for the economy if that complacency gets noticed and acted upon by major players. It may be a good time to look at a new entrant who is providing a service to ease the pains created by the new pandemic; just make sure to do due diligence, because the fraudsters all know that too.
Collectively, I think we're going to have to come to terms with deflationary period. I don't think it can be avoided. At least we shouldn't have to worry about stagflation in the same way They did in the 70's. Oil is uh... Quite plentiful. Unfortunately for those long in the petroleum industry.