With a number of companies reporting today, the one most investors are focusing on is Wells Fargo (WFC 2.73%) because of its heavy ties to the housing market and the overall economic health of the U.S. Based on its falling share price, it's safe to say investors wanted more out of this morning's earnings report. While Wells is not part of the Dow Jones Industrial Average (^DJI 0.06%), it is having some effect on the index today -- more on this later.

As of 12:50 p.m. EST, the Dow is up just seven points, or 0.05%, to 13,478. The Dow's 30 components are currently split, with half trading higher for the day and the other half in the red. Three of the index's big losers are Boeing (BA 0.01%), Bank of America (BAC 1.53%), and Helwett-Packard (HPQ -0.25%).

So why are they down?
Shares of Boeing are down 2.7% today thanks to continuing problems with the new 787 Dreamliner aircraft. Recently, there have been problems with five different 787s in as many days. To make matters worse, each incident was unique: The Dreamliner has suffered a fire, brake problems, a fuel pipe leak, an engine oil leak, and a cracked cockpit window. The Federal Aviation Administration held a press conference today and announced that it would take a closer look into the plane's assembly, parts, and design.

Shares of Bank of America are down 1.8% this afternoon after Wells Fargo announced its earnings this morning and posted worrying numbers in the net-interest-margin category. My Foolish colleague John Maxfield explained earlier today that this is one of the most important metrics in the banking industry, and when it falls at Wells, that's a sign that it has likely fallen at the other big banks.

Lastly, shares of Hewlett-Packard have slipped 1.6%. Yesterday, after the markets were closed, a report was released stating that worldwide personal-computer sales had fallen by 6.4% in the fourth quarter. Some analysts had estimated that sales would fall 4.4% in the last quarter of the year, so the larger decline was a shock to most. In the U.S., PC sales were down 7% for the full 2012 year.