If they go bust won't it likely trigger a massive market crash? Afterall index funds will be forced to sell other US stocks to buy them, bringing their values down. Non-passive investors will predict that and divest even more and so on...
And that is on top of the IPO companies losing value themselves, this seems likely to trigger a doom-loop until the market reaches a low enough value. This will likely trigger layoffs and companies reducing spending and investments further depressing the economy. Added inflation from oil prices and war.
This doesn't seem like one big balloon ready to burst, but more like a house suspended by hundreds of balloons and they are about to be ran over by an airplane.
Yeah, think dot-com crash all over again, but probably worse IMO. Problem is, there really isn't a safe place to hide when this all happens. Some are less unsafe, like funds which track dividend-yielding stocks, or gold I guess (but that's just a speculative value store like bitcoin).