Although investors received the good news that the national unemployment rate had dropped to 7.7% today, many believe the dip was due to the holidays, and workers temporarily stopping their job search. Additionally, the markets were hit with disappointing preliminary consumer confidence numbers for December, but all the mixed economic data today couldn't keep the Dow Jones Industrial Average (^DJI 0.77%) down. The index managed to close the day up 81 points, or 0.62%, and now sits at 13,155.

Today, only six of the Dow's 30 components ended the trading session in the red. This afternoon, I explained why Verizon (VZ -0.09%), Cisco (CSCO 1.69%), and Microsoft (MSFT 1.58%) all moved lower. Read about what caused those three companies to fall into the red by clicking here, or stick around to learn why Alcoa (AA), Pfizer (PFE 0.30%), and Intel (INTC 2.67%) dipped.

So why did they fall?
Alcoa signed a multi-year power contract with the Bonneville Power Administration. The contract runs through September 2022 and will guarantee Alcoa power at a certain price for its Intalco Works aluminum smelter in Ferndale, Washington. While the deal helps Alcoa in cost-controlling measures, it also indicates that the company will remain operating a plant which was built in 1966. Shares of Alcoa closed the day down 0.82% today.  

Shares of Pfizer lost 0.2% of their value today, after a report yesterday announced that the U.K.'s health cost regulator declined to approve Pfizer's Inlyta drug, which is used to treat advanced kidney cancer. The $100 per tablet price tag was considered too high, and Pfizer's offer to offer the drug at a discount was not enough to get the drug past regulators.  

Lastly, shares of Intel closed down just 0.02% today. The company has struggled over the past few weeks as reports have emerged that PC demand continues to slide. Investors seem unsure of the future of the chip maker since it missed the mobile revolution, and other PC chip manufactures have already begun to move toward investor's short sale lists. Advanced Micro Devices (AMD -0.45%), for example. has seen its share price cut in half over the past few months, and recently had more than 27% of its shares sold short.