Warren Buffett's Berkshire Hathaway sharply increased its stake in ConocoPhillips this spring and summer, accumulating a total of 84 million shares as of the end of the third quarter on September 30, according to Berkshire's just-released quarterly portfolio filing with the SEC.
That makes Berkshire the biggest holder of Conoco shares, with 5.6 percent of the shares outstanding.
In mid-May, Berkshire reported holding 17.5 million shares as of March 31. That means Berkshire's stake in Conoco increased almost five-fold over six months.
Its Conoco holdings were kept confidential and not included in its portfolio snapshot released in mid-August for the end of the second quarter. A separate filing tonight reveals that Berkshire held 59.7 million shares as of June 30.
At today's closing price of $47.39, Berkshire's stake in Conoco is worth almost $4 billion, and accounts for 7.3 percent of its U.S. stock portfolio. Conoco's stock has dropped almost 32 percent since September 30. At that point, the stake was worth just over $6 billion.