Apple market value hits $500 billion mark

Apple's stock market valuation has topped the $500 billion mark, making the tech giant the world's most valuable company.

Until now, just six US firms have ever been worth over $500 billion.

While oil giant Exxon was worth that much in 2007, software firm Microsoft was briefly worth $600 billion in 2000, The BBC reports.

Apple has $100 billion of cash reserves on its books, and investors are hoping that it may give some of that back to shareholders this year as dividends or share buybacks.

The market valuation caps a remarkable turnaround for the iPhone maker, whose shares were once worth as little as 3.19 dollars in 1997, when it faced the possibility of bankruptcy.

According to the report, Apple's share price closed at $542.44 on Wednesday on the Nasdaq.