With increased jobless claims, slow business activity in the Mid-Atlantic region, and increased consumer borrowing, the markets are moving lower today. As of 12:45 p.m. EDT the Dow Jones Industrial Average (DJINDICES:^DJI) is down 58 points, or 0.4%, to 14,560. Just a few days ago the Dow looked as if it would soon break the 15,000 mark, but recent earnings reports and economic data have that target looking increasingly distant.

Top Dow losers
Wal-Mart
(NYSE:WMT) is down 1.5% today, even though many believe lawmakers will vote next week on a bill that would impose a tax on all sales made over the Internet. Wal-Mart, the once king of retail, has been hurt over the past few years as customers move to the Internet for lower prices. Part of the reason merchandise is cheaper on the Internet is that sales are not taxed the same way they are when you shop at Wal-Mart or other brick-and-mortar stores. A sales tax on Internet purchases may not close the gap between Internet prices and Wal-Mart's, but it should narrow it.

Shares of McDonald's (NYSE:MCD) are down 0.7% today, even after Deutsche Bank increased its price target on the fast-food chain and maintained its buy rating. However, the company has been dealing with disgruntled employees in New York who are asking for a higher wages and have already begun public protests. This comes at a time when McDonald's has begun a push for better customer service from its employees, so perhaps each side may compromise and get what it wants -- but it could be a costly compromise for McDonald's and its shareholders.

The Dow's biggest loser today is UnitedHealth (NYSE:UNH), which announced earnings this morning. On a per-share basis, income came in at $1.16, which fell short of analyst expectations of $1.14 per share, as well as the prior-year quarter's $1.31 per-share profit. On the revenue side, UnitedHealth posted $30.3 billion compared with $27.3 billion last year, but that was still shy of the $30.5 billion Wall Street wanted to see. Yet these results are not likely the full cause of the shares' 3.7% plunge. The company also announced that a major public-sector customer had switched to fee-based coverage from a full-risk plan, which lowers revenue and profit for UnitedHealth. Additionally, management decided to lower its full-year 2013 sales guidance.

Fool contributor Matt Thalman has no position in any stocks mentioned. The Motley Fool recommends McDonald's and UnitedHealth Group. The Motley Fool owns shares of McDonald's. Check back Monday through Friday as Matt explains what caused the Dow's winners and losers of the day, and every Saturday for a weekly recap. Follow Matt on Twitter: @mthalman5513. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.