Reply #10: The basic idea is that people can't "keep" money.

[Occam Bandage]

Money that rich people "keep" would be wasted, yes, but nobody but Scrooge McDuck has a swimming pool made of currency. It goes *somewhere.* If money is spent, then the seller has money they can spend or invest. If money is put into a bank, then the bank loans it out to people looking to invest in their homes or businesses. If money is put into the stock market, then it is used to buy stocks, which in turn gives businesses money that they can either invest in their business or invest in the market (which would give someone else money they can either invest in their business or in the market). It works well in theory.

That theory is oversimplified. The world isn't Macroecon 101.