Erin Arvedlund- Erin Arvedlund is a journalist who has worked for Dow Jones, The Moscow Times, TheStreet.com, Barron's and the New York Times.  She is author of "Too Good to be True: The Rise and Fall of Bernie Madoff". The opinions expressed are her own. -

Where did all the money go?

After I wrote "Madoff: The Man Who Stole $65 Billion" this was probably the first question I received from almost everyone. And I am forced to tell the bizarre truth: there's probably no money left.

This is the nature of what are known as "Ponzi" schemes, or a classic pyramid scheme--Bernard Madoff constantly had to raise money from new investors to cash out the old investors, or "redeem" them, as a traditional hedge fund or mutual fund would.

But Madoff was not running a traditional hedge fund--not at all. He was running a cash-in/cash-out fraud, using the London branch of his brokerage firm as the piggy bank where he would wire money to and fro to make it look like he was trading for the hedge fund.

But there was no hedge fund, and there was no $65 billion at the end. Madoff lied about the amount of assets he was overseeing.