In the latest salon, he apparently received one about the famous Bitcoin.
Of it, he said, "You can't value bitcoin, because it's not a value-producing asset."
Glancing at it through investor glasses, he added that it wasn't possible to determine how high it will trade for. According to him, there's "a real bubble in that sort of thing."
Elaborating on his remarks, Buffett said bitcoin is "a very effective way of transmitting money, and you can do it anonymously and all that."
He added: "A check is a way of transmitting money, too. Are checks worth a whole lot of money just because they can transmit money?"
He capped his criticism by saying that "the idea that [bitcoin] has some huge intrinsic value is just a joke!"