Apple’s stock broke above $500 for the first time Monday. The company and Exxon Mobile have been trading places (first and second) as the most valuable companies in the world in recent week.

However, Apple’s latest rally has made it 17 % more valuable than the oil company, notes the “Associated Press” (http://macte.ch/waWKT). . Its market capitalization is now $465 billion, compared to Exxon’s $400 billion.