JPMorgan CEO Jamie Dimon has continued to express his disapproval of Bitcoin and other cryptocurrencies, comparing it to a “decentralized Ponzi scheme” and a “pet rock.”

During an appearance on CNBC’s Squawk Box on January 19th, Dimon was questioned about his stance on cryptocurrencies.

He asked the panel why they “waste any breath” discussing the subject before taking a dig at the flagship digital asset, “Bitcoin itself is a hyped-up fraud, a pet rock.”

Dimon also revealed that he was “not surprised at all” by the failure and subsequent bankruptcy of FTX, once one of the leading crypto exchanges in the world, “I called it a decentralized Ponzi scheme.”

He debated saying whether cryptocurrency technology itself is a decentralized Ponzi scheme and what happened to FTX are two different things, and added that “Regulators should have stopped this a long time ago. People have lost billions of dollars if you look at its lower-income people, in some cases retirees.”

Despite Dimon’s criticism of Bitcoin, JPMorgan is actively involved with incorporating blockchain into its services. For instance, the lender has its token dubbed JPM Coin for intraday repurchase agreements. While in December, the bank officially registered a cryptocurrency wallet trademark.

Dimon is known to be a major skeptic of cryptocurrencies, having previously called Bitcoin a ‘fraud.’ He also questioned whether Bitcoin really is a store of value or as scarce as it’s supposed to be, “How do you know it [Bitcoin] is going to stop at 21 million? Maybe it’s going to get to 21 million, and Satoshi’s picture is going to come up and laugh at you all.”