Apple is already the world's most valuable company, and the gap between it and No. 2 Exxon Mobil Corp. has widened rapidly in the past month, as investors have digested Apple's latest earnings report and raised their hopes that the company might institute a dividend.
On Tuesday, it sent out invites to reporters for an event in San Francisco next Wednesday, apparently for the launch of its next iPad model.
Several companies have reached the $500 billion level, but none have held on to it. Exxon was worth just over $500 billion for two short stretches at the end of 2007.
