Sam Bankman-Fried should spend between 40 and 50 years in prison after being convicted for stealing $8 billion from customers of his now-bankrupt FTX cryptocurrency exchange, prosecutors said on Friday.

“His life in recent years has been one of unmatched greed and hubris; of ambition and rationalization; and courting risk and gambling repeatedly with other people’s money,” federal prosecutors in Manhattan wrote. “And even now Bankman-Fried refuses to admit what he did was wrong.”

A jury found Bankman-Fried, 32, guilty in November on seven counts of fraud and conspiracy.

Lawyers for the former billionaire told US District Judge Lewis Kaplan that a 5-1/4 to 6-1/2 year prison term would be appropriate. They said FTX clients would get most of their money back, and that Bankman-Fried did not set out to steal.

Kaplan is scheduled to sentence Bankman-Fried on March 28 in Manhattan federal court.

Bankman-Fried plans to appeal his conviction and sentence.