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.

Wall Street was uncharacteristically cautious Monday, with major indices trading mostly sideways throughout the day as investors await September's delayed jobs report. Wall Street considers the Labor Department's monthly jobs report to be an important economic indicator; institutional investors will shift billions of dollars around after tomorrow morning's report. Analysts expect the report to show a 180,000-person jump in private-sector employment, so any number significantly lower than that may cause a broad sell-off Tuesday. With all eyes to tomorrow's jobs report, the Dow Jones Industrial Average (^DJI 0.27%) shed 7 points, or 0.1%, to end at 15,392.

Beneath the calm surface, however, lay some rebellious big movers: Netflix (NFLX -1.60%) stock, for instance, surged 6.4% as the video-streaming service posted a blowout quarter. Netflix grew its subscriber base by 1.3 million, bringing its running subscription base to more than 31 million viewers. To the cynical minds out there suspicious of how profitable the video service's popularity actually is, rest easy. Earnings shot up more than 300% from the third quarter last year. Netflix shares continued their rise in after-hours trading, at one point tacking on an additional 10% from its closing price. 

Greek shipping company DryShips (DRYS) also defied today's market tranquility, slumping 10% in trading today. Long-term shareholders have probably evolved to become immune to whiplash-inducing moves like today's: Over the past five years, shares lost nearly 90% of their value; in 2013 shares have nearly doubled already; and today, of course, they took a 10% haircut. That's one dangerous roller coaster, and dangerous roller coasters are poor metaphorical investment vehicles. DryShips' reliance on a rocky Mediterranean economy combined with its losses in the trailing 12 months should be enough to make any investor wary. Questionable uses of company funds highlighted by my colleague Blake Bos in a piece last week should also give potential investors pause.

Another, more traditional service-sector stock, Wal-Mart (WMT -0.15%), fell 0.7% Monday, ending as one of the Dow's 17 laggards. Though some retailers have taken to issuing price-matching promotions for the much-awaited holiday season to combat e-retailers, the convenience of online retail continues to woo consumers. With an estimated 90% of U.S. shoppers expected to take to the Web for some purchases this season, Wall Mart's dominant bricks-and-mortar presence may also be its Achilles' heel, as shoppers frequent other retailers for their online purchases.