by , 1:25 PM EST, November 8th, 2007

Earlier this week, Apple's stock hit US$191.79. Thursday, however, was a different story as the company's stock shot up and down -- and at one point dipped down to $167.99.

Apple started Thursday at 186.62 after closing on Wednesday at $186.30. At one point during Thursday trading, the company's stock dropped as much as $18.30 before climbing back above $170.

The Mac and iPod maker's market cap took a hit, too. On Wednesday, Apple was sitting at $167.30 billion, but today that number is down some 18.57 billion to $148.73 billion. In comparison, Intel's market cap currently is $149.27, IBM is at $144.01 billion, and Dell is $62.87 billion. All are down compared to their position on Wendesday.

Apple is currently trading at $$170.50, down 15.80 (8.84%).