Billionaire investor Warren Buffett told CNBC on Wednesday the recent craze over bitcoin and other cryptocurrencies won't end well.

"In terms of cryptocurrencies, generally, I can say with almost certainty that they will come to a bad ending," the chairman and CEO of Berkshire Hathaway said.

"When it happens or how or anything else, I don't know," he added in an interview on CNBC's "Squawk Box" from Omaha, Nebraska. "If I could buy a five-year put on every one of the cryptocurrencies, I'd be glad to do it but I would never short a dime's worth."

Also on the show, Buffett's right-hand man, Charlie Munger, also blasted frothiness in bitcoin — and in venture capital funding.

Earlier Wednesday, the Omaha-based conglomerate announced the appointment of two new vice chairs. Gregory Abel, 55, will be vice chair of non-insurance businesses. Ajit Jain, 66, will be vice chair of insurance operations.

Buffett said he would not take a short position on bitcoin futures.

"We don't own any, we're not short any, we'll never have a position in them," he said.