According to Bloomberg’s Billionaires Index, Mr Buffett is the seventh richest person in the world. He is CEO of the American multinational holding company Berkshire Hathaway.
Speaking to Yahoo Finance, Mr Tull described a piece of advice that Mr Buffett gave him which shaped his approach to investment decisions.
Mr Tull modelled part of his Tulco holding company after Berkshire Hathaway.
The billionaire met with Mr Buffett in his office where the pair conducted a two-hour long conversation.
The lesson Mr Buffett gave involved an approach taken by him and his longtime business partner, Charlie Munger.
Mr Tull told Yahoo Finance: “There was a moment where I was describing and talking through the business model [of Tulco] and how I thought about something.
“I said, ‘What we’re trying to do is be smart about,’ and [Buffett] stopped me and said, ‘I gotta be honest, for years, Charlie and I have always asked, ‘What’s the dumb thing we could do here?’
“I kind of laughed, and he said, ‘No, I’m dead serious. We always ask. We don’t want to be in the clever pile.
“‘What could we do here that would be the dumb thing, and how do we avoid it?'”
“It’s something again, that I bet I’ll treasure forever.”
Mr Buffett is expected to release a widely anticipated annual shareholder letter on Saturday.
The letter will include Mr Buffett’s thoughts on the state of his company, an outlook for the stock market and other topics.