Warren Buffett’s Berkshire Hathaway boosts stake in Occidental Petroleum to about 25% By: MarketWatch May 30, 2023 at 20:34 PM EDT Berkshire bought 4.66 million shares of Occidental between May 25 and May 30, paying roughly $275 million in all. Read More >> Related Stocks: Berkshire Hathaway Berkshire Hathaway Occidental Petroleum