Energy stocks gain, Exxon adds to proven reserves By: MarketWatch February 19, 2013 at 12:26 PM EST Energy stocks gain on Tuesday, with Exxon Mobil Corp. on the rise after the company said it added to its oil and gas reserves. Read More >> Related Stocks: Anadarko Petroleum Apache Corp BP Plc ADR Chevron Corp ConocoPhillips Exxon Mobil First Solar Halliburton Co Schlumberger Ltd Sunpower Corp