I don't know. I'm only illustrating the point that a move, especially one catalyzed by a short term event (COVID lockdowns / fear of long term lockdowns), which is quickly reversed, doesn't have the market-correcting effects that a larger, protracted crash, like 2008, does.

The other thing worth mentioning is that the S&P crashed 58% traumatize in the 2008 crash, while the 2020 move only took the S&P down 36% and for a short period.

Another thing worth noting is that the 1987 crash was actually pretty similar to the 2006 crash, in the sense that it was more of a sudden technical trading disaster, as opposed to a protracted downturn in the markets. In fact, when you look back at a chart (below) from 1975 to the present era, 1987 is just a little blip on the radar.

https://2.bp.blogspot.com/-ii33tZfYl_M/UIjPC5GmG5I/AAAAAAAAAhg/0mcva-nR0Fg/s1600/SNP500_1975_to_Oct2012_Annotated_Techfarm.jpg