By Robert Plummer
Business reporter, BBC News
Wall Street denizen and alleged mega-fraudster Bernard Madoff began his financial career at the age of 22 with just $5,000.
Taking the money raised from summer holiday jobs working as a lifeguard and garden sprinkler installer in the New York borough of Queens, he set up the investment firm that bore his name in 1960.
Mr Madoff's whole legacy has been destroyed, say investors
Now, after nearly half a century of trading, his reputation is in ruins, as he faces allegations that his entire business was nothing more than a $50bn (£33bn) scheme to dupe investors.
With his alleged victims asking why US regulators failed to query what was going on, it seems that the way in which Mr Madoff operated was key to the success of his venture.
While those who knew him describe him as "affable" and "high-profile, but not in a loud way", he went to great lengths to cultivate an aura of exclusivity.
Many of his richest clients were recruited in private chats at upmarket country clubs in New York and Florida, giving them a sense of belonging to a privileged circle of those in the know.
Then he used those big names to attract other investors, until his influence extended to international banks, hedge funds and even charitable foundations.
No-one seems to know yet what exactly has happened to all that money. Mr Madoff is quoted in the US Attorney's criminal complaint against him as saying that he has "absolutely nothing".
Whether he is supposed to have squandered it, stashed it or simply lost it on the markets has yet to emerge.
WHAT IS A PONZI SCHEME?
A fraudulent investment scheme paying investors from money paid in by other investors rather than real profits
Named after Charles Ponzi who notoriously used the technique in the United States in the 1920s
Differs from pyramid selling in that individuals all tend to invest with the same person
In the words of hedge fund boss Douglas Kass, of Seabreeze Partners Management: "It appears that at least $15bn of wealth, much of which was concentrated in southern Florida and New York City, has gone to money heaven."
Mr Madoff's dealings were certainly pretty opaque. As well as his original company, Bernard L Madoff Investment Securities, he ran an entirely separate investment advisory business, which is the firm implicated in the alleged fraud.
He never outlined his trading methods or how he generated the healthy returns on his investors' money.
Somehow, in bad times as well as good, he was able to pay out 10% or more every year. "It's a proprietary strategy. I can't go into it in great detail," he once said.
Prosecutors now think they know all too well what Mr Madoff's "proprietary strategy" was: using money from new investors to pay off old ones, in a form of illegal investment known as a Ponzi scheme, after one of its earliest exponents.
So why did this dubious state of affairs not come to the attention of the regulators sooner?
Well, the answer probably lies in a combination of Mr Madoff's personal prestige and some carefully exploited gaps in the system.
As a former chairman of the Nasdaq stock exchange with a string of other directorships and a generous donor to charitable causes, he was a man who inspired confidence.
Worried investors gathered at the offices of Bernard Madoff in New York
As for the regulators, the US Securities and Exchange Commission (SEC) regularly inspected Bernard L Madoff Investment Securities, but not the separate investment advisory business.
That firm ran a hedge fund which was not registered with the SEC until September 2006 - and, according to reports, never inspected thereafter.
Even so, details have now emerged of earlier SEC inquiries into Mr Madoff's dealings. The SEC said last week that his securities operation was investigated in 2005 and found to have violated rules requiring brokers to get the best possible price for orders.
A second SEC inquiry, in 2007, apparently uncovered no irregularities.
Mr Madoff is said to have told FBI agents that there was "no innocent explanation" for the collapse of his investment scheme.
Many wealthy people appear to have been wiped out by the alleged fraud, while financial institutions around the world are counting the cost.
Saddest of all, some charities are being forced to close because of their losses.
Mr Madoff himself has been released on $10m bail. But if the charges against him are proven, he could face a jail sentence of up to 20 years and a fine of up to $5m.