derekmead writes "Apple, as of this morning, is valued at $621 billion, thanks to a stock price that spiked at $663.10 per share (and that has risen this afternoon). That finally beats Microsoft, who previously held the record for most valuable company in 1999 at $619 billion. Incredibly, Apple has almost doubled its valuation in the last year, when it topped Exxon-Mobil for most valuable American company with a valuation of $346 billion. It's not the cleanest comparison, but to give you an idea of how much $621 billion actually is, only 23 countries had a GDP higher than that in 2011. So, basically, Apple alone is worth more than what 200+ countries in the world could produce in an entire year."