Jamie Dimon, CEO of JPMorgan, believes that there is a fundamental difference between blockchain and cryptocurrency. The latter may have value if embedded with smart contracts, similar to tokenization of physical assets. However, Bitcoin is like a "pet rock," and he advises retail investors not to get involved with it. He also joked that this would be the last time he discusses this controversial asset on CNBC. (Pet rock refers to a stone kept as a pet.)