That sort of crash is what central banks exist to protect against. That could be something like the Fed stepping in as a buyer of last resort and picking up several trillion dollars of equity, and/or pushing rates to zero again to incentivize private capital to more or less do the same.

A global crash of financial systems is unlikely because it’s cause too much pain for everyone. It unfortunately means we plebs are likely the ones paying to bail it out.

I rather suspect that in the current economic climate, a trillion dollar bailout of Big Tech would very quickly translate to riots in the streets.