TIL with the collapse of the American Silicon Valley Bank (SVB) that in Australia, bank deposits are only insured $250,000 per person per ADI bank. Scenario, if you have $1M, you only get 25c for every dollar of your money back. If you have $250,000 in Westpac and St. George ($500,000 total), you'll only get $250,000 back should they collapseas they only have the one ADI licence. Same with nab and ubank.
So, how do the millionaires protect their money? What will you do in that scenario? In the US you can apparently get an insurance to guarantee your savings, but only 3% of the SVB customers have that insurance. I can't find a similar insurance here in Australia.
Oh, and in case it's not obvious…one you deposit your money to a bank, iIT BECOMES THE BANK'S MONEY, and what you have is an IOU.
I'd be surprised if many millionaires kept most of their assets in cash.