Blockchain technology allows the immediate, secure transfer of funds anywhere in the world without a third party such as a bank to facilitate the transaction.
Dimon had the last word. "I was reminded that we move trillions of dollars a day ... digitally. It's not cash."
Dimon told an investor conference last month that bitcoin was a fraud "worse than tulip bulbs." His comments ran contrary to many on Wall Street who have begun to embrace, or at least experiment, with bitcoin and the blockchain technology it utilizes.
During Citigroup's earnings call Thursday, Chief Financial Officer John Gerspach said, "We think the area of cryptocurrency and digital currency is an area worthy of exploration." Gerspach said Citi's labs in Tel Aviv and Dublin are looking at digital currencies, cryptocurrencies and blockchain.
Bitcoin rose more than 8 percent to a record high of $5,231.28 Thursday, according to CoinDesk. Another digital currency, ethereum, traded mildly higher near $307. Many digital currency enthusiasts see ethereum as the foundation for the next generation of the internet.
JPMorgan is already involved in some blockchain-related projects. In 2015, the company began working on Quorum, an enterprise-grade transaction network focused on data privacy and built on ethereum.
The bank then became a founding member of the Enterprise Ethereum Alliance in February, and partnered with the developers of privacy-focused digital currency Zcash in May.