It isn't necessarily a good assumption that someone is taking someone else's profit. More often it's simply people realizing that projected profits won't happen; many of them never existed in the first place.

Crops fail. Promising biotech turns out to be impossible; new drugs are shown to be ineffective. The housing market turns out not-to-go-up-for-ever. A drought in Taiwan stifles semiconductor manufacturing and good chips are hard to find for years; ASML's factory catches fire. Oil spills, and must be cleaned up; Union Carbide leaks gas all over Bhopal. COVID-19 kills people, makes others (rationally) fear for their health, and far less gets done.