NEW YORK -- Every time Apple's stock price goes up, the company sets a new record.
Apple, which already was the most valuable company in the world, became the most valuable in history Monday.
It hit a market value of more than $623 billion, surpassing Microsoft's record from 1999.
Apple is worth almost twice as much the next most valuable company, Exxon Mobil.
Apple stock gained more than two and-a-half percent yesterday, rising more than 17 dollars to $665.15 a share. It keeps climbing amid expectations it will soon launch iPhone 5, and possibly a smaller, cheaper iPad.