I think the ponzi scheme refers to the amount of money flowing around in financial schemes that isn't actually "money". By creating numerous financial products

I think the ponzi scheme refers to the amount of money flowing around in financial schemes that isn't actually "money". By creating numerous financial products and valuations that aren't actually based on assets, the banking system has been able to "print" more money than the central bank would ever allow. And that "money" is what's propping up the stock market. That's why the stock market is no longer representative of the economy: "money" has become an economy in itself.