Jeffrey Epstein was a Gatsbyesque figure who seemed to accumulate Croesus-like wealth out of thin air.
A maths schoolteacher from Brooklyn, he ended up being worth hundreds of millions of dollars, owning a $77 million home in New York, a private jet, and his own island. And no-one has any real idea how.
Financial investigators are now trying to establish where his money came from, and whether it was the product of financial acumen, or something much darker.
Having dropped out of a maths degree at New York University, the career of Jeffrey Epstein began in 1974 as a teacher at the Dalton School, a co-ed prep school, on Manhattan's Upper East Side.
It so happened that one of the pupils was the son of Alan Greenberg, chairman of Bear Stearns, the now defunct investment bank.
In 1976, with no college degree and seemingly no experience in the world of finance, Epstein joined Bear Stearns on the bottom rung, as a floor trader’s assistant.
He spent the rest of the 1970s learning the investment banking world, and climbing the pole, making partner extremely quickly in four years.
Epstein left Bear Stearns hurriedly, due to a minor securities infringement in which he loaned $20,000 to a friend to buy stock. He was also rumoured to be having an affair with a secretary.
He went on to set up is own firm, called Intercontinental Assets Group, which he ran out of his small New York flat.
It was then that he had a second serendipitous meeting, this time with Steven Hoffenberg, chief executive of Towers Finance Corporation.
Amid the 1980s corporate raiding frenzy, epitomised by the film Wall Street, Epstein was behind a failed plan to take over Pan Am, according to Hoffenberg. Another bid for a freight airline also failed.
Epstein then struck out on his own with his investment company J. Epstein & Company, which was later called Financial Trust Co.
His business model was simple. Epstein said he would only take clients who could give him over 1 billion to invest on their behalf.
He charged them a straight fee, and they signed over power of attorney, including the power to sign cheques and buy property for them.
What did other Wall Street figures make of Epstein?
Epstein was an enigma on Wall Street. Other hedge fund executives said all they knew about him was that he held big parties, and seemed to know famous people.
Many were suspicious of his claims to have a small, secretive list of billionaire clients. No-one ever traded with him, worked with him, or knew who his clients were.
As one hedge fund executive said: "It’s hard to make a billion dollars quietly." Another said: " I never once heard of him or his firm or anyone who worked or traded with him."
According to a court document from 2002 Epstein said his company employed only 20 people, and they were in "administrative" roles.
Clients would come to see him at his home.
Was he running a Ponzi scheme?
More than one financial expert has pointed out apparent similarities between the financial operations of Epstein and Bernie Madoff.
Not revealing his "billionaire" clients, basing himself in the US Virgin Islands, the lack of staff, and the wall of secrecy around his company, have drawn suspicion.
Then there is his early connection to Hoffenberg, often described as his mentor. In 1995 Hoffenberg pleaded guilty to a massive $463 fraud that was one of the biggest Ponzi schemes in history. He was jailed for 20 years.
Last month, Hoffenberg, who one owned the New York Post, claimed, in a sworn affidavit for a court case, that Epstein was involved in his crimes.
He said: "Epstein has remained free and has used and benefited from the ill-gotten gains he amassed as a result of his criminal and fraudulent activities.”
Two weeks ago he told CBS News: "He [Epstein] was my best friend for years. My closest friend for years. We ran a team of people on Wall Street, investment people that raised these billion dollars illegally. He was my guy, my wing man."
If Epstein's investment firm was a Ponzi scheme he somehow managed to keep it going thought he financial crisis, while he was simultaneously being jailed for sex offences in Florida.
Was Epstein blackmailing and extorting wealthy clients?
Having obtained the contents of Epstein's safe the FBI may already know the answer.
According to this theory Epstein could have forced wealthy individuals to give him their money to invest by putting them in compromising situations with young women. The women, underage or not, could have been deployed as "honey traps".
Virginia Giuffre, who claims Epstein held her as a "sex slave," said she was forced to have sex with some of Epstein's "powerful friends" and he would quiz her about it afterwards, seeking "embarrassing information."
Alleged victims of Epstein described him making angry phone calls and seemingly threatening people he knew.
Once he had obtained large amounts of money, Epstein could have placed it in tax free offshore accounts, or simply invested it in the stock market, making large amounts for himself, and for those he had blackmailed if he chose to give it to them.
There could also have been a money laundering dimension to his activities.
About 15 years ago $88 million suddenly appeared in very small company in the Virgin Islands linked to Epstein.
It is not clear where it came from, and it was then gradually removed over the following years.
Do we know who any of his financial clients were?
Only one name is public, that of Leslie Wexner, chief executive of L Brands, which owns Victoria’s Secret.
Epstein got to meet Mr Wexner through another senior executive who introduced them around 20 years ago. Mr Wexner was worth $1.8 billion.
Epstein apparently charmed Mr Wexner into signing over power of attorney to him in 1991.
Mr Wexner later said: "I think we both possess the skill of seeing patterns. But Jeffrey sees patterns in politics and financial markets, and I see patterns in lifestyle and fashion trends."
In 1998 Epstein bought his island in the US Virgin Islands. The same year he bought his house in New York from Mr Wexner. Epstein signed both sides of the deal.
Mr Wexner severed ties with Epstein in 2007 after the first sex allegations against him surfaced. He went on to accuse Epstein of having misappropriated "vast sums" of money.
According to Mr Wexner's lawyers Epstein ultimately returned about $100 million.
Was Epstein really a financial genius?
No. He may have presented an illusion of genius, but what we do now is that he suffered some heavy losses.
In the three years to 2005 Epstein invested $80 million in a hedge fund that later collapsed, and it was unclear how much he got back.
He still had 100,000 shares in Bear Stearns when it failed during the financial crisis.
And he lost another $50 million he had in a Bear Stearns fund centred on mortgage-backed securities, which collapsed.
Epstein reportedly cooperated with authorities prosecuting those who ran the fund. At the same time he was negotiating his plea deal in Florida on sex charges.
What did the big banks know about him?
Investigators have obtained his records from banks to see if it provides any clues about the sources of his wealth.
In recent years he had accounts with JPMorgan Chase and Deutsche Bank, which he used to trade.
According to those who dealt with him earlier, when he was a customer of Bear Stearns, he was aggressive and demanding. One former Bear Stearns employee called him a "tiger".
At one point Epstein sued Citigroup. And he made a complaint to regulators abut Bear Stearns.
His litigiousness extended to other areas of his life, becoming involved in disputes with a speedboat company and an interior designer. The interior designer called him "abusive" and a "nightmare".
How much was he worth in the end?
According to his will, Epstein listed assets of $577 million.
That included $194 million in hedge fund investments, $112 million in shares, $56 million in cash, and $18 million in planes, boats and cars.
He had properties in the US Virgin Islands, New York, Florida, New Mexico, and PAris.
Where it all really came from, and how, is still anybody's guess.