Apple market value has climbed past $623bn (£396bn), surpassing the record set by Microsoft during the heyday of technology stocks in 1999.
Apple shares rose 2.6 per cent, bringing its gains this month to almost nine per cent as Wall Street bets on the 12 September rollout of the latest version of the iPhone, the device that revolutionised the mobile industry.
Microsoft, however, retains the title of history's most valuable company if its 1999 peak value of about $621bn were to be adjusted for inflation.
Apple's stock usually rallies in the run-up to major product launches, among the most heavily watched events on the annual tech calendar. The iPhone is the company's biggest product, yielding half or more of its sales.
Sources have said the company will take the wraps off a larger version of its iPhone on 12 September. Some analysts also think it intends to announce a smaller iPad to safeguard its market share, as rivals from Google to Amazon begin selling cheaper, seven-inch tablets.
City A.M. Reporter