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 pinning their hopes on aspirations for an unequivocally positive employment report, bullish investors made their disappointment obvious after the actual Labor Department numbers this morning were much less encouraging. The unemployment rate did plunge from 7% to 6.7% in December, but the nearly half a million people who left the labor force was the primary reason for that decline. Gains of just 74,000 nonfarm payroll jobs sent the Dow Jones Industrials (^DJI 0.69%) down 40 points as of 11 a.m. EST, with early morning indications of a substantial rise for the Dow disappearing after the report. Yet in looking at declines of Chevron (CVX 0.57%), UnitedHealth Group (UNH -1.03%), and other stocks, it's important to look beyond the impact of the jobs data to see other causes for the drop.

For instance, Chevron fell 1.6% after issuing its interim update last night, which included preliminary results for the fourth quarter. The oil giant said earnings would be roughly flat compared to the third quarter, with rising net income from downstream refining and marketing operations offsetting weakness in upstream exploration and production activity. In particular, falling oil and liquids production in the U.S. more than offset a slight climb in natural gas production domestically, while a much larger plunge in natural gas production overseas offset a modest climb in oil and liquids volume. Moreover, substantial sequential drops in oil prices, as well as international natural gas realizations, could hurt dollar revenue as well.

Meanwhile, UnitedHealth dropped 1.3%. Rival insurer Humana (HUM 0.82%) said late yesterday that it sees unfavorable trends among those enrolling in private plans through Obamacare health-insurance exchanges, pointing to the ability of some customers to retain their nonexchange insurance coverage. The news confirms worries throughout the industry that weak enrollment figures suggested that insurers weren't seeing the ideal mix of healthier and less healthy enrollees. Further evidence could cause problems for every insurance company in the industry.

Still, not all the news was bad. Intel (INTC -0.38%) rose 1.7% despite news that PC shipments worldwide fell another 10% during 2013. Yet investors have to remember that at some point, the rate of decline becomes more important than the fact of the decline, and even a slower fall in PC demand could lead to positive surprises for Intel. In that light, any successes Intel has on the mobile front could represent icing on the cake for investors.