How did rising coronavirus cases catch investors by surprise?

US stocks close down 3.5% as Covid concern mounts

FT 28 October 2020

But the pandemic never went away, and the threat of an autumn rebound in cases as cooler weather returned was long identified as a potential risk.

That’s far from a black swan, an improbable and unforeseen event that has an enormous impact.

So why do investors seem surprised?

Englund