H-P rises on Icahn rumor, but Apple slips By: MarketWatch December 10, 2012 at 11:13 AM EST Shares of Hewlett-Packard Co. jump as speculation spread on Twitter that billionaire investor Carl Icahn was building a position in the technology giant. Read More >> Related Stocks: Apple Cisco Systems Groupon Cl A Hewlett-Packard Intel Corp NVIDIA Corp PHLX Semiconductor Sector Index SanDisk Corp