Sam Bankman-Fried, the founder of the FTX cryptocurrency exchange who was convicted of stealing billions of dollars from customers

, was sentenced to 25 years in prison on Thursday, capping an extraordinary saga that upended the crypto industry and became a cautionary tale of greed and hubris.

Mr. Bankman-Fried’s sentence was shorter than the 40 to 50 years that federal prosecutors had sought after a jury found him guilty of fraud, conspiracy and money laundering — charges that carried a maximum penalty of 110 years behind bars. But the punishment was far above the six and a half years requested by his defense lawyers.

Mr. Bankman-Fried, 32, did not visibly react as Judge Lewis A. Kaplan handed down the sentence in Federal District Court in Manhattan. His parents, the law professors Joe Bankman and Barbara Fried, sat two rows from the front, staring at the floor.

“He knew it was wrong. He knew it was criminal,” Judge Kaplan said of Mr. Bankman-Fried’s actions.

Before the sentence was delivered, Mr. Bankman-Fried, cleanshaven and wearing a loosefitting brown jail uniform, apologized to FTX’s customers, investors and employees.

“A lot of people feel really let down, and they were very let down,” he said. “I’m sorry about that. I’m sorry about what happened at every stage.” He added that his decisions “haunt” him every day.

Mr. Bankman-Fried was also ordered to forfeit $11.2 billion in assets.