So far, so good. "But at noon, they have tons of money left. They have all this supply, and the, what I would call 'legitimate' demand – it's probably not a good word – but where risk and reward are still in balance, has been satisfied. But they're still open until five. And around 3:30 in the afternoon they get to such things as subprime mortgages, OK? And what you guys haven't seen yet is what happened between noon and 3:30."

Straightforward economics tells us that when you print too much money, it loses value and prices go up. That's been happening too. But Mr. Forstmann is most concerned with a different, more subtle effect of the oversupply of money. When it becomes too plentiful, bankers and other financial intermediaries end up taking on more and more risk for less return.

The incentive to be conservative under normal credit conditions is driven in part by what economists call opportunity cost – if you put money to use in one place, it leaves you with less money to invest or lend in another place. So you pick your spots carefully. But if you've got too much money, and that money is declining in value faster than you can earn interest on it, your incentives change. "Something that's free isn't worth much," as Mr. Forstmann puts it. So the normal rules of caution get attenuated.

"They could not find enough appropriate uses for the money," Mr. Forstmann says. "That's why my little bank story for the kids is a fun way to put it. The money just kept coming and coming and coming and coming. What are you going to do with it? IBM only needs so much. The guy who can really pay his mortgage only needs so much." So you start thinking about new ways to lend the money, which inevitably means riskier ways.

"I don't know when money was ever this inexpensive in the history of this country. But not in modern times, that's for sure."

Combine this with loan syndication and securitization, and the result is a nasty brew. Securitization and syndication allow the banks to take the loans off their books and replenish their capital. They then use this capital to make new loans, which they securitize or syndicate and sell to the hedge funds, which buy them with the money they borrowed from the banks. For a time, everyone makes money.

In fact, for six years, a lot of people made a lot of money in this environment. So much money that, as Mr. Forstmann notes, the price of admission to the Forbes 400 list of the richest Americans has gone from $500 million 10 years ago to over $1 billion today. (Mr. Forstmann was bumped from the list two years ago, his reported 10-figure net worth no longer enough to keep pace.)

At the same time, both the size and the number of hedge funds and private-equity funds have ballooned. "I used to have one of the biggest private-equity funds in the world," he says matter-of-factly. "It was, I don't know, $500 million or a billion dollars. If you don't have a $20 billion fund now, you're kind of a (nobody)," Mr. Forstmann says. (The term he used to describe those of us without $20 billion PE funds was both more colorful and less printable than "nobody.") "And so what does that tell you?"

Mr. Forstmann hasn't raised a new fund in four years. But he doesn't blame the hedge funds or the private-equity funds – they are not the villains in his story. "Fundamentally, I don't see them as a cause," he says. "Obviously the proliferation of hedge funds and private-equity funds has created its own dynamic. But this proliferation is simply a result of the vast increase in the money supply."

Mr.