Apple's stock has hit a new high after a four-month swoon, as investors are looking ahead to the release of a new iPhone model, and possibly a smaller iPad, AP reported.

Already the world's most valuable company, Apple Inc. saw its stock hit $644.13 in morning trading Friday, August 17 before retreating to $642.

The previous high for the stock was $644, hit on April 10.

Apple has a market value of $602 billion, almost 50 percent higher than No. 2 Exxon Mobil Corp. at $408 billion.

Apple's stock fell last month after the company's earnings report for the April-June quarter showed the slowest growth in more than two years. It was only the second time in 10 years that Apple had missed analyst expectations.