"It won't end well. Someone is going to get killed," Dimon said at a Barclays banking conference. "Currencies have legal support. It will blow up."
Why it matters: Dimon has been pessimistic about bitcoin and other cryptocurrencies in the past, and has argued that there will never be a currency "that gets around government controls." And Dimon isn't the only critic. Other analysts have argued that bitcoin is nothing more than a fad with no value, and have warned that the currency's current market success could create an economic bubble.
Market reaction: Bitcoin stock fell roughly 0.8% after Dimon's comments.