When it comes to bitcoin, billionaire investor Warren Buffett wants to make one thing clear: Unlike buying stocks, bonds or real estate, buying bitcoin is not an investment.
That's because it lacks intrinsic value, Buffett says.
"If you buy something like bitcoin or some cryptocurrency, you don't have anything that is producing anything," Buffett says in an interview with Yahoo Finance. "You're just hoping the next guy pays more. And you only feel you'll find the next guy to pay more if he thinks he's going to find someone that's going to pay more.
"You aren't investing when you do that, you're speculating."
"Put together a portfolio of companies whose aggregate earnings march upward over the years, and so also will the portfolio's market value," Buffett wrote in his 1996 letter to shareholders. "If you aren't willing to own a stock for ten years, don't even think about owning it for ten minutes."
To be an investment, what you're buying has to be worth something on its own, Buffett says.
For example, "If you buy something [like] a farm, an apartment house or an interest in a business and look to the asset itself to determine whether you've done something — what the farm produces, what the business earns ... it's a perfectly satisfactory investment," Buffett explains to Yahoo Finance. "You look at the investment itself to deliver the return to you.
"If you ban trading in farms, you could still buy farms, and have a perfectly decent investment," Buffett says.
Bitcoin, however, only increases in value by being bought and sold, he argues. Its value comes from what people are willing to pay.
"[I]f you ban trading in ... bitcoin, which nobody knows exactly what it is, people would say, 'Well why in the world would I buy it?'"
The Oracle of Omaha has held this opinion since at least 2014, when he told CNBC of cryptocurrencies, "It's a mirage basically."
"The idea that it has some huge intrinsic value is just a joke in my view," Buffett said.
In 2017, bitcoin soared from below $1,000 at the start of the year to over $19,000 in December, catching the attention of everyone from J.P. Morgan Chase CEO Jamie Dimon to NFL players. Tuesday, bitcoin traded near $8,900 according to CoinDesk's price index.
Buffett sees a bleak future for the digital currency.
"I did not think [founder Jeff Bezos] could succeed on the scale he has," Buffett said to shareholders in May 2017.
Crypto-enthusiasts argue that Buffet doesn't understand blockchain-based coins, and he has admitted as much.
Still, many other investing experts like CNBC's Jim Cramer, Kevin O'Leary and Tony Robbins, also call buying cryptocurrencies a gamble. They suggest thinking of it like rolling the dice in Las Vegas.
"As long as you can afford to lose everything you put into it, go with it," O'Leary told CNBC Make It in December, 2017.
That mindset is alright with Buffett.
"There's nothing wrong with it if you want to gamble [that] somebody else will come along and pay you more money tomorrow," Buffett tells Yahoo Finance. "That's one kind of game. That is not investing."
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