Facebook, Microsoft weigh on tech; Apple volatile By: MarketWatch October 28, 2013 at 09:29 AM EDT Facebook and Microsoft shares retreat as the tech sector begins the week on a wobbly start. Apple is volatile ahead of earnings. Read More >> Related Stocks: Apple Cisco Systems Facebook Groupon Cl A Intel Corp Microsoft PHLX Semiconductor Sector Index SanDisk Corp Texas Instruments Yelp Inc Zynga Inc Cl A