Warren Buffett made a bold bet on a couple of oil stocks before he retired as Berkshire Hathaway's (BRKA 1.24%)(BRKB 1.33%) CEO earlier this year. His company bought nearly 27% of Occidental Petroleum's (OXY +1.49%) outstanding shares and built a 6.5% stake in oil giant Chevron (CVX +1.70%), making them Berkshire's sixth- and fourth-largest holdings, respectively. Those moves have paid off this year as crude prices skyrocketed due to the war with Iran. Here's a look at why these top oil stocks remain a safe ...