Although we don't believe in timing the market or panicking over daily movements, we do like to keep an eye on market changes -- just in case they're material to our investing thesis.

After taking a breather for Labor Day, Wall Street resumed trading on Tuesday and investors were decisively bullish nearly the entire day. As the session progressed, however, the vociferous, hawk-like rhetoric of leaders in Washington gave the impression that the calm before the storm was nearing its end. In other words, impressive U.S. manufacturing numbers and better-than-expected construction spending were the only things keeping stocks elevated with a Syrian military intervention gaining political support. The S&P 500 Index (SNPINDEX:^GSPC) gained 6 points, or 0.4%, to end at 1,639 Tuesday. 

Energy drink company Monster Beverage (NASDAQ:MNST) plummeted 5.9%, but the fall isn't merely the result of a few jittery investors pulling their hair out over paranoid worst-case-scenarios. It's arguably even less substantive: Twitter rumors are circulating that hedge fund golden boy David Einhorn is shorting Monster shares. While Einhorn has had success in the past -- he put his money where his mouth was and made a fortune shorting Lehman Brothers before its bankruptcy -- an unconfirmed viral rumor about his portfolio is hardly a compelling reason to dispose of the stock. 

Ensco (NYSE:ESV), an oil and gas drilling company with a fleet of company-owned and operated rigs, shed 2% after its stock was downgraded by Barclays, which now gives the shares an equal weight rating, down from overweight. With rising tensions in the Middle East, some investors may be looking to cash out on holdings in the region that could be affected by drawn-out violence or even lasting uncertainty, and Ensco owns rigs in the Middle East, the Asia-Pacific rim, the Mediterranean, and other regions. 

Finally, Pepco (NYSE:POM) lost 1.8% despite a lack of grumpy analysts booing the stock. The $4.6 billion utilities company mostly peddles electricity but also sells natural gas. While the stumble was bad enough to land Pepco on today's list of notable underperformers, the slip isn't really as bad as it seems. The utilities sector as a whole was down nearly 1.3% today, so its performance isn't far off from its peers. From a long-term view, the dip is just a meaningless bump in the road. 

Fool contributor John Divine has no position in any stocks mentioned. You can follow him on Twitter @divinebizkid and on Motley Fool CAPS @TMFDivine.

The Motley Fool recommends and owns shares of Monster Beverage. 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.