if this is the way we're going to behave, then cap the maximum size of accounts at the FDIC coverage limit (implement account software in Rust, not C, no overruns :) If you go over this amount, the bank should automatically create a new account for you and put the excess in there. done, you're 100% insured, we don't have to do anything special to protect you. . Probably that means (I don't know the regs) that the ban…
It would have to be a new account at a different bank. FDIC coverage is per bank, per depositor, and per ownership category (e.g. single vs joint account).
but if you're right, it seems a little silly, why impose that "diversification" on bank customers? if 100 millionaires live in a city, why should they all have accounts at all the different banks, as if that's somehow safer for the FDIC than have the same funds spread around in the same quantities across the same banks, just under different names.