First, on New Year's Eve last year, Buffett's Berkshire Hathaway owned $174.3 billion worth of Apple stock. Second, at the end of the first quarter of this year, so March 31, that had dropped to $135.4 billion.

Berkshire Hathaway significantly reduced its enormous stake in Apple in the first quarter, as Warren Buffett's conglomerate let its cash hoard swell to a record $189 billion.

Berkshire Hathaway CEO stressed relationship at annual meeting attracting Apple CEO Tim Cook, Bill Gates and Bill Murray

Berkshire's investment in the iPhone maker is still the biggest one in the $364 billion portfolio at $135.4 billion.

Warren Buffett paid tribute to his late business partner Charlie Munger at Berkshire Hathaway's annual meeting on Saturday, while reassuring shareholders that the executives expected to succeed him were ready for the job.