Key TakeawaysWarren Buffett's Berkshire Hathaway has added to its holdings of shares of Occidental Petroleum and SiriusXM Holdings.According to regulatory filings, Berkshire Hathaway purchased 8.9 million shares of Occidental Petroleum and 5.0 million shares of SiriusXM Holdings.Shares of both companies have tumbled this year, hitting their lowest levels of 2024 yesterday. Shares of Occidental Petroleum (OXY) and SiriusXM Holdings (SIRI) advanced about 4.5% and 10%, respectively, on Friday after billionaire ...