This is digression (so what, I like digressions)- Principal Trust (Alberta) is a weird example (Do not confuse with Principal in the U. S.).
It was deep-sixed by the provincial government because of opposition by the old line banks and the Alberta Treasury Branch.

I was one of those with certificates. The funny part of it was that Principal had considerable assets that more than covered its debts.
The trustees in bankruptcy periodically disposed of the assets and paid the proceeds to the certificate holders. This was done over several years, I received the final installment about two years ago. Lo and behold, there was a small profit, even after the trustees took a cut!
The moral- In Canada, don't compete with the old boys.
The rate paid was only 2% or less over the payment by other lenders on savings certificates; interest rates were going crazy at the time and people were really shopping around for deals.

Now some larger investors bought bonds or some such- really buying a piece of the company- I forget the drill, that was years ago- and they lost a hefty percentage.
One such loser was one of the Alberta Hutterite Colonies. The boss bought a chunk of the action with reserve funds. I learned about it because an elder from another of the Colonies, a good friend of mine, did the investigation into the Colony finances.

Some innocents did lose quite a bit, but many of the bond (or whatever the notes were called) buyers I knew were pretty wild investors and Principal was just one investment, and they shrugged it off. It was a time of investment frenzy, some of them 'insider' tips and thus illegal, passed from washroom cubicle to cubicle.

Now things are quite different; the loan companies and banks have various funds, some quite risky and about as forthcoming as a slot machine. Canadians love to gamble.

Getting back to the super-rich, I guess Bill Gates is one of them. He and his friends built Microsoft into a company with $50 billion income in 2007. $31 billion was returned to shareholders (including Gates), the rest invested in research or left in reserve. The Company has 79,000 employees, 47,000 in the U. S. Now that is an engine creating money.

Get an Economics 101 textbook and learn all about it.