Warren Buffett: Apple is 'probably the best business I know in the world'

Warren Buffett is a man who knows how to make money. So when he says that Apple is 'probably the best business I know in the world,' it's probably wise to listen to him.

He was speaking during an interview with CNBC, with his company Berkshire Hathaway reportedly ending 2019 with a 5.7% ownership in Apple stock.

So just how important is Apple to Berkshire Hathaway? Pretty important, it would seem.

Warren Buffett told CNBC that Berkshire Hathaway's "third largest business," after its insurance and railroad interests, is its stake in Apple.

"I don't think of Apple as a stock. I think of it as our third business," Buffett said on Squawk Box.

"It's probably the best business I know in the world. And that is a bigger commitment that we have in any business except insurance and the railroad," he said.

Berkshire counts both insurance giant Geico Auto Insurance and North American railroad BNSF as wholly owned subsidiaries.

Also interesting was the news that until recently, Buffett has been using an old flip phone. That's changed, however, with a shiny new iPhone warming his pockets. Alongside his overstuffed wallet, presumably.

Buffett, a self-admitted Luddite, resisted using an iPhone, in favor of his flip phone, even as Berkshire doubled down on Apple stock. But on Monday, he told CNBC that he finally gave in and switched to an iPhone.

"My flip phone is gone," he said. "I've been getting several of them" over the years, including from Apple CEO Tim Cook.