[user104658]

Really the important thing to note is that when we're talking about this money - it's almost ALL in terms of net worth/stocks/financial holdings not physical assets or currency. It's "theoretical money" not money with liquidity that they actually have in the bank - which is why he can be "technically so rich" but still in trouble when it comes to things like X which is leveraged on stock. Market fluctuations can make billions appear or disappear over-night. A sustained drop can mean that lenders swoop in and take everything.