Earnings announcements are driving the Dow Jones Industrial Average (^DJI 0.09%) today. As of 12:30 p.m. EDT the index is at 13,543, down 0.06%. Only six of the Dow's 30 components are in the red thus far, but due to the weight the six carry, the index is being pulled lower.

The three biggest losers today are International Business Machines (IBM 1.03%), Intel (INTC 0.24%), and UnitedHealth Group (UNH -0.02%).

So why are they down?
IBM is the biggest drag on the Dow today, down 5.26%. Last night the company posted earnings that missed analyst estimates on revenue. Although IBM met most of the other analyst expectations, the company didn't change guidance for the full 2012 year. Most investors hadn't expected IBM to raise earnings, and this shows that things may not be as good as they currently seem.

Last night Intel also announced earnings, which revealed that profit dropped 14% in the third quarter. Investors have been concerned that a PC slowdown would hurt the company, and the earnings report proves they had reason. The company posted net income of $2.97 billion, down from $3.49 billion of the third quarter last year. All the news was not bad: The company increased its gross margin to 63.3%, which was higher than what it predicted. The company is currently trading lower by 3.04%.

Finally, UnitedHealth is moving lower by 1.86% following its earnings release yesterday morning. While net income increased by 23% and the company crushed estimates on earnings with $1.50 per share where analysts expected $1.34, the company did miss on revenue. The company's CEO also let analysts know that their expectations for 2013 may be too high. My Foolish colleague Dan Caplinger believes these comments are why the stock has lost value.