The term to google for is "insured cash sweep", but the specifics depend on the ...

The term to google for is "insured cash sweep", but the specifics depend on the particular financial institution you work with. Instead of a single insurance provider, your cash is sharded behind the scenes among many member institutions. Here's one bank I picked at random from Google[0]. Brokerages like Schwab[1] and IBKR[2] also have a private insurer (both use Lloyd's of London) they offer as a service to customers.