I can't recommend e-banking enough. Through Fidelity you can purchase CDs from a number of banks across the country, shopping for the best interest rates. And you can create an auto-rolling CD ladder if that's your thing. I presume other e-banks like Schwab have similar features. Then you can manage all these things in one place, while getting the benefit of having your funds FDIC insured because they're technically CDs at multiple banks behind the scenes.

I would think money market mutual funds are a more liquid, easier, higher yielding version of that. They don’t have the FDIC insurance, but they’re well diversified and invest in the highest grade of bonds, and “breaking the buck” (holding less than enough to redeem all deposits) is extremely rare.

From 2008 - ???, money market accounts were offering 0% interest, while CD's provided some small rate of return.

*A common use-case for millionaires. FDIC limits are $250,000 per-institution, per-account owner, per-account type (CD, money market, savings, checking) and my understanding is joint accounts are considered separate owners so two spouses could have up to $750,000 in CDs at a single bank and be fully insured.

30% of households have an aggregate net worth above 250k. So the situation GP in describing is probably very common.

But the majority of that 30% with a net worth above $250k have most of it in the form of their house, not CDs.

The portion of households that have $250k in the bank is no doubt much less than 30%.

I don't believe that most high net worth households are that cash heavy.

I have well over $250k net worth, the vast majority of our assets are in brokerage and retirement accounts. We have only $60k in cash.

I think my credit union expires every 90 days :-/