With rates as low as they were, there was massive investment in speculative ideas from whales like Softbank ($4B loss in Vision Fund) along with an unknown amount of Sovereign Wealth Funds, hedge funds and family offices (Shadow Economy). These were the guys moving that smart money needle. If any of these bets were hedged, like hedge funds used to operate, the trade was likely too large and crowded to even be offset. Sounds so cliche but higher rates popped the bubble.
Don't forget about the individuals who plowed money that was created out of thin air into crypto, PTON, AMC, Gamestop, SNOW, TDOC, WING, ROKU, etc, who are now down enormously. Celsius network failing had a big part in this, but it also goes to show how ridiculous things got when you could make a 13% yield risk free when treasuries were yielding less than 1%.
Not much of either investment was even real - in the end it was all money that didn't even exist. The idea of filling startups with cash or giving cash to companies that will soon be gone is not a long term strategy if the company cannot execute on that money. The business cycle worked and did what needs to happen in a capitalism based economy. In this case, I think it's safe to say that maybe one or two of those 50 high flying stocks will break even decades away, but everything else will go to zero or be acquired.