Facebook valuation highlights S&P 500 power shift By: CNBC.com News June 23, 2015 at 18:17 PM EDT Facebook is now more valuable than Wal-Mart, which highlights a wider power shift at the top of the S&P 500 index. Read More >> Related Stocks: AT&T Inc Apple Atlantic Power Corp Chevron Corp Exxon Mobil Facebook Google, Inc. International Business Machines JPMorgan Chase & Co Microsoft Procter & Gamble Sentinelone Inc Cl A Wal-Mart Stores, Inc. Wells Fargo