With a high net-worth, can you keep your emergency fund in stocks?

[Tim]

"My issue is more about getting over the psychological barrier of keeping ~270K in the bank:"

You know the right answer. You worked your tails off for awhile to reach a point of comfort. You made a life style choice, live with it. Not in your risk tolerance.
FOMO needs to be conquered.

[xraygoggles]

I personally keep 50k cash in checking account. No real reason why I chose that number, it's just a nice round number that's big enough for any immediate liquidity issues.

Bad idea in terms of investment, but it's not an investment - it's for my peace of mind. No price on that.