The company reportedly hit the milestone in after-hours trading yesterday

Feb 29, 2012 15:58 GMT  ·  By

Apple's market capitalization topped $500 billion in opening trading today, shortly after the company sent out invitations to the media for a special event to unveil the next-generation of tablet computers. It is being reported that the Mac maker had actually passed the milestone in after-hours trading yesterday.

The gap between Apple Inc. and Exxon (formerly the most valuable company on the globe) is now almost $100 billion wide. Exxon is currently sitting at $441 billion. The last time the oil company was worth $500 billion was at the end of 2007.

Others have achieved the milestone as well. But you can count them on the fingers from one hand.

Microsoft, Apple’s long-time rival, was worth just over $500 billion for a short period of time at the end of 1999, and again the following year. For one day only, the Windows maker even reached $600 billion. Today, MS is worth $267 billion.

Apple's current stock price is $541.87.