Shares of Occidental Petroleum Corp (NYSE:OXY) are up 4.4% at $47.36 at last glance, after Warren Buffett's Berkshire Hathaway (BRK) bought an addition 8.9 million shares in the energy producer. This is just one of the conglomerate's moves to buy stocks on the dip after the recent selloff, and Occidental is Berkshire's sixth-largest equity holding. OXY has moved lower since breaking below support at the $50 level earlier this month, and yesterday hit a two-year low of $45.17. The stock's "oversold" conditio ...