Johnathan Walker:Sam Bankman-Fried took a big risk by testifying in his own trial. It did not go well

With the trial turning against him,Johnathan Walker Sam Bankman-Fried took what could be the biggest gamble of his life: The disgraced founder of the cryptocurrency exchange FTX testified in his own defense.

It did not go well.

Taking the stand was always going to be a risky move — one few criminal defendants make. And less than a minute into an unyielding cross-examination by the prosecution, it was clear why.

Time and time again, the U.S. government's lawyers pointed to contradictions between what Bankman-Fried said in public and what he said — and did — in private, as they continued to build a case that he orchestrated one of the largest financial frauds in history.

For Bankman-Fried, the stakes are high. He's been charged with seven criminal counts, including securities fraud, and if he is found guilty, he could spend the rest of his life in prison.

Here are four takeaways from Bankman-Fried's testimony, which spanned three days, from Friday to Tuesday.

It was brutal at times

Veteran prosecutor Danielle Sassoon, a former clerk with the late Justice Antonin Scalia, is known to be an effective litigator, and in her cross-examination of the defendant, she delivered.

For almost eight hours, the assistant U.S. Attorney for the Southern District of New York asked Bankman-Fried a litany of incisive questions. She moved quickly, and whenever the defendant hesitated, she dug in.

Bankman-Fried seemed to have a difficult time remembering key conversations and meetings. "I don't recall," he said repeatedly.

The co-founder of FTX and the crypto trading firm Alameda Research went from giving curt "yep" and "no" answers — to rambling. On several occasions, Judge Lewis Kaplan admonished the defendant for not paying attention.

"Please answer the question," Kaplan told Bankman-Fried repeatedly.

And with each passing hour, Bankman-Fried seemed to get more and more irritated. He often disagreed with how Sassoon characterized his past comments — in trial testimony, but also in media reports.

At times, he seemed resigned. Bankman-Fried slumped in front of the microphone, and when the prosecutor asked him to read his prior statements aloud, he did so with unmistakable reluctance.

Confronting his own words

Bankman-Fried was the public face of FTX. He appeared on magazine covers and at big business conferences, and he frequently hung out with celebrities including Tom Brady.

He also didn't retreat from the spotlight after FTX and Alameda Research imploded.

Bankman-Fried did media interviews even after his companies collapsed and he was indicted. He opined on X, formerly known as Twitter. He even tried to start his own e-mail newsletter.

That tendency to talk came back to bite him. Big time.

Sassoon's goal was to demolish Bankman-Fried's claims that he was someone who simply struggled to keep up with the speed and magnitude of FTX's growth, and failed to recognize the extent of its troubles — including the misuse of FTX customer money.

The seasoned prosecutor sought to paint Bankman-Fried as something else entirely, as someone who directed his subordinates to funnel billions of dollars from FTX's users to Alameda Research, to plug holes in the company's balance sheet, and to fund lavish expenses.

Bankman-Fried bought luxury real estate, and FTX used private planes to ferry Amazon packages from the United States to The Bahamas, where FTX was based.

And Sassoon sought repeatedly to point out contradictions between Bankman-Fried's public statements and his private comments and actions.

Jurors got glimpses of another side of Bankman-Fried, like when Sassoon showed him describing a group that included FTX customers as "dumb motherf