“Just beware.”

That’s Jamie Dimon, CEO of Wall Street investment bank J.P Morgan Chase, who spoke Thursday to CNBC during a segment alongside billionaire investor Warren Buffett. During the joint interview, both Dimon and Buffett were asked about their views on cryptocurrency – a subject that, for the two, has sparked more than a degree of controversy.

Indeed, Dimon infamously branded bitcoin a “fraud” last fall – though he later reportedly said that he regretted those comments.

Today, his remarks were far more measured, with Dimon telling the network (according to a published transcript):

“I– I don’t wanna be the bitcoin spokesman. You know, just beware.”

Buffett remarked Thursday that he believes he’s set a “high standard” with his commentary – he said in January that cryptocurrencies “will come to a bad ending” – and added that “I don’t know whether Jamie can top me or not.”

The outspoken billionaire also said in May that bitcoin, to him, is “rat poison squared.”

“[Bitcoin] itself is creating nothing,” he told CNBC at the time. “When you’re buying nonproductive assets, all you’re counting on is the next person is going to pay you more because they’re even more excited about another next person coming along.”

Image Credit: CNBC