You still need a buffer to pay for expenses...$3000 to someone with Upper Income is not a lot. I don't think anyone is liquidating assets to pay for their electric bill.
Expenses can be paid from margin and credit, and that paid back when the income lands in the brokerage or cash management account. Credit cards are usually ~20 days float, margin is 1-2% for as long as you’re extended with it (ignore margin rack rate on brokerage sites, high net worth folks aren’t paying that).
Higher level, being poor is expensive and it gets cheaper and easier to get ahead as you get ahead.
Credit cards are at least 20 days - you also have on average 1/2 a month before the monthly statement, and then another 20 days until the statement is due.
