http://www.macrumors.com/2008/07/21/apple-stock-plunges-10-after-earnings-released/

Apple's stock has plunged over 10% in after hours trading since Apple announced record and expectation beating 3rd Quarter results, currently sitting at just under $150 after closing at $166.49.

Apple's stock price is notoriously volatile after quarterly conference calls due in part to Apple's habit of understating estimates for future quarters which they routinely beat. In addition to a low forecast, Apple's gross margin was lower than the year ago's quarter.

apple's stock seems like a roller coaster, it goes way down one day and it goes way up another day

that's right. it seems that it's done that for years though

yeah i know, remember when it was down to $50, now it's up to 166

right, but it was over $200 at one point

yeah, it was, that was only like a few months ago

yeah i know