If the US falls apart, your startup will too. No matter how well preserved your cash reserves are.
The US going to war or entering hyperinflation is probably at the bottom of most founders lists of existential worries. Not a risk to mitigate (it’s a risk you need to accept since there’s nothing you can do - worrying about it won’t help)
Also, worth mentioning that no one lost money with SVB’s collapse. One might argue it was an incredibly smart decision for YC to recommend people bank at SVB since if SVB goes under, virtually all LP’s and everyone in the VC community will go under too (too big to fail, so they won’t, or if they do, everyone else fails too — kind of like AWS us-east-1)
