It's quite a lot more important to diversify funds for procedural risk than bank failures, although SVB certainly illustrates that they do happen.
More likely, the bank will put a ~$1b hold on your account while they investigate suspicious transactions, and your options are to whistle, sing, scream, or twiddle your thumbs until they are done.
So having 4-5 total accounts, ideally unrelated to each other in terms of legal owners (differently-named subsidiaries are usually the way to go, I understand, though I am far from an expert in such matters), will enable you to continue to operate your business while bank A does compliance on your accounts.
If you run into a situation where banks A through F all put holds on your account, you need a good RICO lawyer or equivalent. Different class of problem, and different likelihood of happening, and the kind of thing a great CFO plans around.
More likely, the bank will put a ~$1b hold on your account while they investigate suspicious transactions, and your options are to whistle, sing, scream, or twiddle your thumbs until they are done.
So having 4-5 total accounts, ideally unrelated to each other in terms of legal owners (differently-named subsidiaries are usually the way to go, I understand, though I am far from an expert in such matters), will enable you to continue to operate your business while bank A does compliance on your accounts.
If you run into a situation where banks A through F all put holds on your account, you need a good RICO lawyer or equivalent. Different class of problem, and different likelihood of happening, and the kind of thing a great CFO plans around.