Forget about Europe. The Dow Jones Industrial Average (INDEX: ^DJI) caught a wave higher at the open this morning, as favorable earnings results from several Dow components pulled the average up more than 100 points early in the session before settling back to a more modest 74-point gain. The broader market trailed the Dow, as the tech-heavy Nasdaq actually fell in advance of key earnings reports.

Even within the Dow, a few stocks didn't manage to post gains. Let's take a closer look at the Dow's losers today.

Wal-Mart (NYSE: WMT), down 3%
The fallout from yesterday's news that Wal-Mart's Mexican subsidiary was allegedly involved in a bribery scandal continued today, as the company started to take steps to address the problem. Wal-Mart named a global compliance officer to ensure that the company meets the requirements of the Foreign Corrupt Practices Act and to oversee a team of compliance directors throughout its international markets.

Meanwhile, although the scandal has led to some Congressional attention and a Justice Department investigation, the Mexican government has thus far taken no action. It's still unclear whether Wal-Mart's business prospects will suffer from the allegations, but shareholders seem to be selling first and asking questions later.

Cisco Systems (Nasdaq: CSCO), down 1.3%
Cisco didn't release any big news today, but investors got some interesting insight from Juniper Networks (NYSE: JNPR). Originally scheduled to release earnings after the market closed, news leaked out early, prompting a brief trading halt before shares reopened much higher. Juniper beat consensus estimates for first-quarter sales and earnings, although guidance for the coming quarter wasn't nearly as optimistic.

The news from Juniper is just one more example of how competitive Cisco's industry has become lately. Despite its size, Cisco won't get a free pass to future growth; it'll have to figure out how to regain the vast competitive advantages it once held.

McDonald's (NYSE: MCD), down 0.6%
McDonald's has been riding on a bullish wave of sentiment for years now. After having survived the financial crisis almost unscathed, the company has seen huge international expansion bolster its results.

But earlier today, Fool contributor Alyce Lomax suggested that McDonald's may have trouble keeping its success going after CEO Jim Skinner leaves later this year. Having turned the company around from an also-ran to a leader that has challenged not only fast-food peers but also gourmet coffee sellers, Skinner will be tough to replace -- and shares may get volatile if doubts about successor Don Thompson arise.

Earnings season is far from over
Earnings will drive gains and losses over the next few weeks, so it's essential to track earnings announcements as they come. The Motley Fool thinks you should focus on five stocks with key results for this earnings season. But don't delay; accept this special invitation before these companies report.