Apple's stock fell 12 percent today, its worst tumble in four years. Nobody knows if this is the beginning of the end, or a lull between two glorious chapters of market dominance.
What we do know is that Apple lost an eighth of its market cap today, or $52 billion in stock value. That's more than the market cap of some very big, very famous companies (h/t Rebecca Jarvis for the first comparisons) ...

Big picture: This says as much about the monstrous size of Apple (which just "disappointed" with $54 billion in revenue last quarter) as it does about the size of today's sell off.
This article available online at:
http://www.theatlantic.com/business/archive/2013/01/today-apple-stock-lost-more-than-the-market-value-of-nike-or-starbucks/272506/