Warren Buffett’s Berkshire passes Exxon Mobil in market cap rankings By: MarketWatch March 06, 2015 at 15:48 PM EST Warren Buffett’s Berkshire Hathaway rises to third place in the market-cap tables, pushing Exxon Mobil to fourth. Read More >> Related Stocks: Berkshire Hathaway Berkshire Hathaway Exxon Mobil Google, Inc. Microsoft