SAN FRANCISCO (MarketWatch) - Facebook Inc.'s FB, -0.89% has, so far, added $20 billion to its market value this week, as the stock rallied to a new high after the social network's impressive second-quarter report. Facebook's market cap last stood at $195.4 billion, up about 11% from Friday, according to data from FactSet. Facebook's market cap also has surpassed those of other major tech giants, including IBM Corp. Intel Corp., Cisco Systems and Amazon.com. Facebook was last trading up 7% to $76.18.