Jamie Dimon is having second thoughts about bitcoin.

For months, the JPMorgan Chase (JPM) CEO was one of bitcoin's most vocal high-profile critics. He called the digital currency a "fraud", predicted that governments would "crush it" and even threatened to fire any of his bankers if they traded it.

"If you're stupid enough to buy it, you'll pay the price for it one day," he said in October.

That was just one of many critical comments about bitcoin, "which I regret making," Dimon said during an interview with Fox Business on Tuesday.

In the interview, he said blockchain -- the technology that underpins bitcoin -- is "real" and said it is important to look at cryptocurrency offerings individually.

"You can have cryptodollars and yen and stuff like that," he said.

JPMorgan did not respond to a request for comment.

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Some fans of the cryptocurrency saw Dimon's comments as vindication, and poked fun at him for changing his tune as the price of bitcoin went up.

"Shorter Dimon -- 'I called Bitcoin a fraud before I knew how much money we could make trading it,'" Michael Shea tweeted.

Shorter Dimon- "I called Bitcoin a fraud before I knew how much money we could make trading it." — Michael Shea (@cirrusdriver) January 9, 2018

The digital currency's price soared 1,300% last year. It started 2017 trading at less than $1,000 and topped $19,000 in December.

However, Dimon made clear he was not going to become a cheerleader for bitcoin any time soon.

"I'm not interested that much in the subject at all," he said.

More mainstream investors are exploring bitcoin after several exchanges started listing futures late last year. But the cryptocurrency remains extremely volatile, routinely moving up and down by over $1,000 within hours.

It was trading at $14,700 on Tuesday.

-- Daniel Shane contributed to this article.