Apple is the second largest company in America based on its market value, after oil giant Exxon Mobil. Apple is ahead of other public corporations with higher revenue, including Wal-Mart, Procter & Gamble, Berkshire Hathaway, and AT&T. Wall Street analysts say that Apple's value is based on its rapid growth, which is not matched by any other huge U.S. company. The extremely brisk sales of Macs, iPhones, and iPads are likely to accelerate as Apple picks up more sales overseas and takes market share in the U.S. from companies such as Research In Motion, maker of the Blackberry, and Dell.

The case for a continued rise in the value of Apple's shares is compelling. It posted record revenue of $20.34 billion and net quarterly profit of $4.31 billion, or $4.64 per diluted share, in the quarter that ended September 25th. Revenue was up 66% from the same quarter a year ago. iPhone sales rose 91% to 14.1 million. Many analysts who cover Apple's stock believe that the iPhone growth rate will continue at a similar pace.

The total value of Exxon Mobil's shares creates a market cap of $362 billion. Apple's is $284 billion. Exxon's quarterly revenue is over $90 billion, but that figure is not growing very quickly. Neither is the world's largest company's stock price. It has risen by 5% in the last year. Apple's stock is up 65% over the same period.