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.

The Dow Jones Industrial Average (DJINDICES:^DJI) continues its trek lower this week. The Dow has shed 40 points as of 2:15 p.m. EST, with its biggest movers diving into the red after jobs data disappointed investors with a fresh round of economic concern. Among top blue-chip stocks, Chevron's (NYSE:CVX) taking a big hit after announcing a worrying trend for its fourth-quarter production, while Pfizer's (NYSE:PFE) among the Dow's leading laggards in the health care sector. Let's catch up on what you need to know.

One very bad jobs report
The jobs reported blindsided investors today with severely unexpected bad news, as payrolls added just 74,000 new jobs in December. That wasn't just the worst monthly mark for 2013: It marked the slowest increase in jobs for one month since January 2011, adding new speculation that the economy's rise is still sorting out bumps in the road. Economists had expected that more than 190,000 jobs would be added to the economy in December.

As a lone bright spot, the U.S. unemployment rate did fall to 6.7%, the first time it had declined below 7% in five years. That's not due to job gains, however -- it's because nearly 350,000 Americans gave up looking for jobs and dropped out of the labor force in December. While the economy did add a total of 2.2 million jobs in 2013 -- roughly what 2012 produced, a strong number -- the U.S. economy's growth needs a lot higher job growth than December's meek number.

Chevron's not inspiring much confidence in investors today, either, as the Big Oil stock is down 2% to lead all Dow laggards. The company announced today that its fourth-quarter net profit will stand roughly on par with the third-quarter profit mark of $5 billion after Chevron's gas and oil production fell. The company's 2.56 million barrels of crude oil produced during October and November is a 3.9% year-over-year drop, following weakening demand that has hit production across several of the company's competitors as well.

Falling demand has affected Chevron's finances in a bad way lately, as the company's revenue fell by 4.7% and its earnings per share also declined over the first nine months of 2013. While analysts are optimistic about a return to production growth in 2014, investors have to hope oil prices make a comeback for the majors in the new year.

Pfizer stock is down around 1% after Cowen downgraded the Big Pharma from outperform to market perform. While Pfizer has had a strong 15.5% run-up over the past year, there's no reason to panic just yet about this company's ability to perform in the new year. The worst of the patent cliff is over for Pfizer, after plunging revenue to former top-selling drug Lipitor slammed sales last year. Expect those losses to ease in the new year, while up-and-coming drugs such as Xeljanz and Eliquis, which struggled to gain much traction last year, should start to garner momentum in 2014.