I think some brokers try to account for it.
IB, for example, on their website they say that they distribute your account cash out to different banks so that you don't hit the FDIC limit on any one bank. That does require you to interact with them and black list banks that you already have money in, however, because the only way they know to avoid it with your account is to tell them to avoid it. Not advice, or recommendation, just an observation of their website.
Edit, it looks like an optional program you can join with IB called the Insured Bank Deposit Sweep Program.
Yeah but you will still hit the SIPC limit. Hard to imagine that there are institutions that actually trade with IB as well as so advertised by IB. How do they manage these account limit issues?
