Former crypto tycoon Sam Bankman-Fried has admitted he made "mistakes" in how he ran his collapsed FTX exchange - but told a court he did not steal from its customers.
The 31-year-old also acknowledged a "lot of people got hurt" when the company went bankrupt as he testified in open court in his fraud case for the first time.
Bankman-Fried's trial began earlier this month with accusations he stole more than $10bn (£8.2bn) from FTX customers.
He earlier had taken the stand on Thursday, but without the presence of the jury, while the judge in the case decided which portions of his evidence would be admissible.
Bankman-Fried told the court on Friday he made "a number of small mistakes and a number of larger mistakes" while running the exchange, but said there was never any intention to defraud or steal from anyone.
He said the biggest mistake had not been implementing a dedicated risk management team.
Under questioning from his own defence lawyer, the entrepreneur added: "We thought that we might be able to build the best product on the market. It turned out basically the opposite of that.
"A lot of people got hurt - customers, employees - and the company ended up in bankruptcy."
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Bankman-Fried has pleaded not guilty to two counts of fraud and five counts of conspiracy and could face 115 years behind bars if convicted.
Prosecutors claim he used customer funds to make risky bets at sister trading firm Alameda Research - with a huge black hole in the company's finances emerging when crypto markets suffered a sharp downturn.
The trading platform abruptly halted withdrawals last November and subsequently went bankrupt.
FTX used to be the world's second-largest exchange and Bankman-Fried was worth $32bn (£26bn) on paper.
He was known for rubbing shoulders with A-list celebrities and advising US politicians on how the industry should be regulated - as well as his big curly hair. Commentators in the US have even noted how he has recently had a new, shorter haircut.
The prosecution will cross-examine Bankman-Fried later. The case continues.