To most of the Bitcoin community, Jamie Dimon is a villain. The Chairman, CEO and President of JPMorgan Chase—the largest bank in the United States—has been expressing skepticism the cryptocurrency for about as long as Bitcoin believers have been telling one another to “hodl.”

Bitcoin chart
Chart of Bitcoin's value.

Dimon first dipped his toes into the Bitcoin conversation with a healthy dose of negativity back in 2014 when the chief executive told CNBC that Bitcoin is a “terrible store of value” and “could be replicated over and over.”

Among Dimon’s criticisms of the cryptocurrency was the fact that it hadn’t achieved any form of legitimacy and lacked the type of backing that allows a fiat currency to maintain its value. “It doesn’t have the standing of a government,” he warned.

Dimon also noted that Bitcoin’s uses were often questionable at the time. “A lot of it is being used for illicit purposes. And people who will get upset with it is governments,” he said. “Governments put a huge amount of pressure on banks: know who your client is, did you do real reviews of that. Obviously it’s almost impossible to do with something like that.”

Because of that, he suggested that Bitcoin would have difficulty ever achieving mainstream acceptance. “The question isn’t whether the the bank accepts bitcoin...the question is do we even participate [with] people who facilitate bitcoin,” he said.

Shortly after Dimon’s comments—which aired on CNBC on January 23, 2014—Bitcoin’s value dipped. The cryptocurrency had been rising steadily to above $860, but quickly dropped back down to $800 one day after Dimon spoke negatively of it.

Bitcoin bounced back slightly but it was short-lived. In the weeks that followed Dimon’s comments, Bitcoin continued a downward slide that cost the cryptocurrency more than one-third of its value.

Dimon again took aim at the cryptocurrency late in 2015 while speaking at the Fortune Global Forum on November 4. On stage, Dimon said in his “personal opinion” there will be “no real, non-controlled currency in the world. There is no government that's going to put up with it for long ... there will be no currency that gets around government controls."

When asked about the potential for Bitcoin to become the basis for a “shadow economy” run by entrepreneurs and technologists, Dimon said, “It’s just not going to happen. You’re wasting your time.”

At the time, Bitcoin was already reeling a bit, hovering around the $350 range. The currency defiantly—albeit briefly—jumped to $400 shortly after Dimon’s comments started making the rounds. The gains were short-lived, though, as the cryptocurrency quickly dropped back down to around $320.

By the fall of 2017, Bitcoin had made up for its lost value and then some. It was reaching a fever pitch, jumping from being valued at under $1,000 at the start of the year to over $4,000 by the time Dimon again made comment on the cryptocurrency.

Perhaps the most damning and most controversial opinion Dimon has expressed about Bitcoin came on September 12 of last year. While speaking with Bloomberg , the head of the biggest financial institution in the U.S. condemned Bitcoin and those who invested in it.

“It’s a fraud,” the head of JPMorgan Chase said of Bitcoin, not mincing words despite the cryptocurrency’s skyrocketing value at the time. When asked what he would do if he learned one of his employees started trading in Bitcoin, Dimon said he’d take swift action.

“I'd fire them in a second,” he said, giving two reasons for the decision. “It’s against our rules, and they’re stupid. And both are dangerous.”

Dimon said in the conversation that his daughter had purchased some Bitcoin and he acknowledged the underlying technology behind the cryptocurrency may have promise—though noted its adoption wouldn’t happen overnight.

Still, the overview from Dimon for Bitcoin remained negative. “If you were in Venezuela or Ecuador or North Korea or a bunch of parts like that, or if you were a drug dealer, a murderer, stuff like that, you are better off doing it in bitcoin than U.S. dollars,” he said. “So there may be a market for that, but it’d be a limited market.”

Bitcoin dipped in value briefly in the days after Dimon’s harsh criticisms, dropping the cryptocurrency below the $4,000 barrier and sending it as low as $3,001 before it began to recover and return to the value it had achieved earlier in the month.

On October 13, Dimon again went at Bitcoin. He told attendees at the Institute of International Finance that those who opted to invest in Bitcoin would one day lose their investment. “If you're stupid enough to buy it, you'll pay the price for it one day," he said.

Dimon went on to say he had little interest in what the perceived value of Bitcoin was at, warning that its success would be short-lived. "The only value of bitcoin is what the other guy will pay for it," Dimon said. "Honestly I think there's a good chance of the buyers out there are out there jazzing it up every day so that maybe you'll buy it too, and take them out."

Bitcoin crossed the $5,000 barrier for the first time the day before Dimon’s comments and investors were not scared away despite the warnings. The cryptocurrency fell just short of $6,000 within the next few days and spiked to above $7,000 in the weeks that followed Dimon’s criticism.

Bitcoin continued its rise in the months that followed, peaking at as high as $19,998 in December before dropping slightly. By the start of the new year, Bitcoin continued to hover around the $15,000 mark.

The apparent increase in interest and success of the cryptocurrency made Dimon back off his comments slightly. On January 9 of this year, Dimon walked back his comments calling Bitcoin a fraud.

“I regret making” those comments, Dimon said in an interview with Fox Business. “The blockchain is real. You can have crypto yen and dollars and stuff like that.” He also admitted in the conversation that he is “not interested that much” in the subject of cryptocurrency.

At the time, Bitcoin’s value had started to slide. It had lost $2,000 of its value in the last two days and the slide didn’t stop despite Dimon’s apparent turnaround on the cryptocurrency. Bitcoin dipped below $15,000 the day Dimon went on Fox Business and slipped under $14,000 within the next few days.