Victims arrive to hear the sentencing
Bernard Madoff listened to emotional statements from his victims at a New York court as he awaited sentencing for running a $65bn (£40bn) fraud.
Madoff, 71, apologised and said that he would "live with this pain, this torment for the rest of my life".
Madoff pleaded guilty to 11 charges in March and could face a sentence of up to 150 years in jail.
But his lawyer is asking for a 12-year sentence. It remains unclear if investors will get any money back.
District Judge Denny Chin, who is presiding over the case, said that the guidance range for sentencing was 150 years but he was not bound by it.
"I must impose a sentence that is reasonable," Judge Chin told the court.
Victims of the fraud have called for a tough sentence.
"Life has been a living hell. It feels like the nightmare we can't wake from," said Carla Hirshhorn, one of 10 victims to speak in the court.
"May your jail cell be your coffin," Michael Schwartz told Madoff.
Madoff, who wore a dark suit and lowered his eyes while listening to the witnesses, will also read a statement before the judge hands down a decision.
In a preliminary hearing on Friday, Judge Chin ordered Madoff to forfeit $171bn in assets, while his wife Ruth had to forfeit more than $80m in net worth she claimed was hers.
Victims of Bernie Madoff's scam, Cindy and Richard Friedman
The giant figure Madoff was ordered to forfeit was equal to the sum prosecutors said had passed through his investment firm over the years. In practice, however, such funds do not exist.
Under the order the Madoffs must sell a $7m Manhattan apartment where Ruth Madoff lives.
Other assets to be sold include an $11m estate in Palm Beach, Florida, a $4m home in Montauk and a $2.2m boat.
But an agreement with prosecutors has enabled Ruth Madoff to keep $2.5m in cash.
The trustee winding down the Madoff firm has collected $1.2bn to return to investors.
Bernard Madoff has admitted defrauding thousands of investors in a Ponzi scheme which he said had been running since the early 1990s.
The 11 charges he pleaded guilty to included securities fraud and money laundering.
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
Speaking before the start of the court hearing, Ira Sorkin, Madoff's lawyer, said his client "will speak to the shame he has felt and to the pain he has caused".
"We seek neither mercy nor sympathy," said Mr Sorkin. But he has asked Judge Chin to "set aside the emotion and hysteria attendant to this case," as he determines the sentence.
However, the sentence is expected to be long.
"Given the enormous amount of funds he has stolen and the number of victims, the sentence is going to be very, very high," said Paul Radvany, a law professor at Fordham University in New York.
The hearing will take place in a courtroom that can accommodate 250 people.
Two separate rooms in lower Manhattan courthouse will house former investors and spectators to watch on closed-circuit TV.
The list of Madoff's investors includes film director Steven Spielberg's charitable foundation, Wunderkinder.
UK banks were also among the victims with HSBC Holdings saying it had exposure of around $1bn. Other corporate victims were Royal Bank of Scotland and Man Group and Japan's Nomura Holdings.
But it is not just the elite and large firms who were victims of the fraud.
School teachers, farmers, mechanics and many others have also lost money.
Many had benefited from their investments until Madoff was arrested in December.
Madoff started his financial career aged 22 with $5,000 from money made from summer holiday jobs such as working as a garden sprinkler installer in New York.
He then set up Bernard L Madoff Investment Securities in 1960.
His firm became one of the largest market-makers - matching buyers and sellers of stocks - and Madoff served as chairman of the Nasdaq stock exchange.
As well as wealthy individuals, investment advisory firms were key Madoff investors.
Madoff's firm was investigated eight times by the US Securities and Exchange Commission over the past 16 years, because it made exceptional returns.
But it was the global recession which effectively prompted Madoff's demise as investors, hit by the downturn, tried to withdraw about $7bn from his funds and he could not find the money to cover it.
Madoff estimated the fraud totalled $50bn, but prosecutors said that weeks before Madoff's arrest in December, the firm's statements showed a total of $65bn in its accounts.
He has always insisted he acted alone in masterminding the fraud.
The only other person who has been charged is his accountant David Friehling, 49, with aiding and abetting fraud, and four counts of filing false audit reports. He has been released on bail.
Though Mr Friehling was not charged with knowledge of the Madoff Ponzi scheme, he was charged with deceiving investors by falsely certifying that he audited the financial statements.