shares boosted by Warren Buffett's comments

Shares in Amazon, which have more than doubled since the start of 2017, rose more than 3 per cent in early trading on Friday.

Results were released before Buffett, 88, and Vice Chairman Vice Chairman Charlie Munger, 95, were expected to answer more than five hours of questions from shareholders, journalists and analysts at Berkshire's annual meeting. Knowing this, a headline that Berkshire Hathaway was buying shares in Amazon would understandably generate interest in the markets.

According to the report, Buffet said that one of his colleagues that manages the money in the office had bought Amazon to show up in the 13F quarterly filling report. Buffett did not say how many shares of Amazon Berkshire had bought. "I hope [Buffett] lives forever, but that's probably not a good bet". That was more than the $1.3 billion that Berkshire, which historically has preferred using its cash on equities or acquisitions, spent all of past year after relaxing its policy on buybacks.

Buffett's stock picking has tended to favor nuts-and-bolts sectors such as banking, airlines and food companies. By contrast, Amazon's shareholders have allowed Bezos to expand aggressively at the expense of delivering consistent profits.

"Yeah, I've been a fan, and I've been an idiot for not buying" Amazon shares, Buffett said on CNBC Thursday.

Buffett's experience in investing in technology companies has not always been positive. While Berkshire Hathaway's stake in Amazon might not be a game changer, it could decrease some of the valuation concerns. "I have admired Jeff for a long, long time but I did not think he could succeed on the scale that he has". Its last major acquisition was in January 2016. The company also this week pledged $10 billion to help finance Occidental Petroleum's bid to beat out rival Chevron take over Anadarko Petroleum.

Buffett's assistants did not immediately respond to a message seeking comment.