Berkshire Hathaway (BRK-A), a major holder of Occidental Petroleum (OXY), continues to accumulate shares. Last week saw a 2,137,250 share buy, valued at $122.1 million. That’s the first buy in nearly a month, following multiple buys in May. Berkshire, run by Warren Buffett, now owns over 25 percent of the oil company, and has permission […]