The 97-year-old berkshire Hathaway vice chairman abandoned bitcoin during a question-and-answer session on Wednesday, calling it "too unstable" to be considered a global exchange.

At the Daily Journal's annual meeting hosted by Yahoo Finance, Charlie Munger asked one of those present what he considers the biggest competitive threat to U.S. banks in the long run.

The question, focused on a potential technological glitch by the likes of Amazon and Apple Pay, digital wallets and bitcoins, prompted Munger to say he did not know how the payment system would evolve.

However, the Berkshire executive said he did not think bitcoin would become a global exchange, calling it an "artificial gold substitute."

"Since I never buy gold, I never buy bitcoins," Munger said. "I recommend that other people follow my practice."

The Daily Journal Corporation, an American publishing company headed by Munger, owns stakes in Bank of America and US Bank.

"I really believe that a well-managed bank makes a big contribution to the development of civilization and that the world's central banks like to control their banking system and their own cash reserves," he said.

Munger then paraphrased Oscar Wilde's quote about fox hunting, saying bitcoin reminded him of those buying a nascent asset class as "a pursuit of the indescribable-unimaginable."

During the nearly two-hour session, many questions were asked about bitcoins. Asked whether his opinion on cryptocurrencies remained the same or whether the Daily Journal would consider bitcoin as an asset on the balance sheet, as in the case of the investment game Tesla Revent, Munger briefly rejected this possibility.

"No, we're not going to follow Tesla in the direction of bitcoin," he said.