The markets opened mixed with the Dow losing 12 points to 12,642 while Nasdaq added 7 points to 2369. Federal Reserve Chairman Ben Bernanke warned Congress of a shrinking economy for the first half of the year.

On the upside

Best Buy (NYSE: BBY) posted slightly lower earnings, but results for the nation's largest consumer electronics retailer beat estimates. Same-store sales declined, but international sales more than offset the weakness.

Immucor (Nasdaq: BLUD) reported 3rd quarter profits that beat expectations. Analysts promptly upgraded the blood testing equipment maker.

Shares of Micron Technology (NYSE: MU) rose ahead of its earnings report later today.

On the downside

Shares of biotechnology company Medarex (Nasdaq: MEDX) lost ground after a rival with a similar drug reported negative results which bode ill for this drug research company.

LoJack (Nasdaq: LOJN) lowered its guidance for the year blaming a decline in overall car sales. The vehicle tracking device maker was promptly downgraded by analysts.

Crocs (Nasdaq: CROX), the maker of colorful plastic shoes, was downgraded by an analyst due to weak U.S. demand leading to an inventory build-up.

In the broad market, declining issues outpaced advancer by a slim margin on the NYSE and by nearly 5 to 4 on Nasdaq. The Russell 2000 which tracks small cap stocks lost 2 points to 708.