NEW YORK — Former Wall Street investor, Sung Kook "Bill" Hwang, has been sentenced to 18 years in prison in a massive fraud case that cost banks billions of dollars.

The sentence comes after Hwang was found guilty of fraud and market manipulation in a case linked to the failure of his investment fund Archegos Capital Management in 2021.

"The amount of losses that were caused by your conduct are larger than any other losses I have dealt with," US District Judge Alvin Hellerstein said before announcing the sentence, in quotes cited by Reuters news agency.

The prison term was slightly shorter than the 21-year prison sentence sought by prosecutors, but is still unusually long for a white-collar crime.

Prosecutors had also been seeking a restitution payment but the judge has not announced his decision on the matter. The sentencing hearing is set to resume on Thursday.

Hwang was found guilty of lying to major investment banks as he secretly amassed large bets on several companies.

When Archegos was unable to repay its lenders, it prompted a mass sell-off of stocks and the fund quickly collapsed in less than a week, making it one of the largest hedge fund collapses since the 2008 financial crisis.

Among the major banks that suffered huge losses as a result of Archegos' implosion were Credit Suisse, which has since become a part of UBS, Japan's Nomura and Morgan Stanley.

Hwang's lawyers had called for him not to be punished, citing his Christian faith and his donations to charity.

They also said his wealth, which at one point was valued at an estimated $30bn (£23.7bn), had fallen to an estimated $55m.

The judge called the requests for leniency "utterly ridiculous" due to the money involved and compared Hwang to the disgraced founder of FTX, Sam Bankman-Fried, who received a 25-year sentence for fraud last year, according to Bloomberg.

Hwang's lawyers did not immediately respond to a request for comment from the BBC.

Hwang's deputy at Archegos and co-defendant, Patrick Halligan, who was also found guilty on three criminal charges at the same trial, is set to be sentenced at a hearing scheduled for 27 January. — BBC