Key Takeaways Shares in Occidental Petroleum (OXY) are in focus Monday after a regulatory filing released late Friday revealed that Warren Buffett's Berkshire Hathaway (BRK.B) has added to its sizable stake in the oil and gas exploration and production company. The purchases, valued at roughly $153 million, give Berkshire 28% interest in the energy producer, through Buffett wrote in the 2023 shareholder letter that the investment firm has no interest in acquiring or managing the company. Rather, he pointed ...