Shares of Apple stock jumped up 2 percent on Monday, the first day of trading in the new year, launching Apple's market capitalization past the $300 billion mark for the first time in the company's history.

Three and a half years after breaking the $100 billion barrier, Apple's market capitalization has now reached a new milestone.

Investors displayed renewed confidence in Apple's 2011 plans by lifting the company's stock seven points to $329.57 at close of market on Monday. The gains added $6 billion in value to the Mac maker, bringing its market capitalization to $302.32 billion.

The Cupertino, Calif., company, however, still trails behind Exxon Mobil Corporation, the world's highest-valued public company. Exxon Mobil also saw impressive gains of nearly 2 percent, bringing its market cap to $375.92 billion.

Apple grabbed the second place spot by overtaking PetroChina Co. in September. The company also made headlines in May when it passed its long-time rival Microsoft in terms of market capitalization. Shares of Apple passed the $300 mark in October.

The milestone comes as further evidence of what has been called the "the greatest comeback story of all time." In December, MarketWatch named Apple's Steve Jobs "CEO of the Decade" for bringing the company back from the brink of bankruptcy and building it into the largest technology company in the world.

Despite its already record high, shares of Apple stock are expected to continue to increase in value, with some analysts predicting a $500 "bull case" share price.

On Monday, Piper Jaffray analyst Gene Munster reiterated his 12-month price target of $438 for Apple, while telling investors that Apple will probably just improve on its existing product lines in 2011, rather than releasing a new product.