Stocks step up at Wednesday open

NEW YORK (CNNMoney.com) -- U.S. stocks gained ground at Wednesday's open as investors absorbed a surprise gain in January retail sales.

The Dow Jones industrial average rose nearly 0.5%. The Nasdaq composite index added 1.2%. The Standard & Poor's 500 index was 0.6% higher.

Affecting the markets Wednesday:

Retail sales: Retail sales posted a 0.3% rise in January, far better than a forecast of a 0.3% decline, as well as the the 0.4% drop in December.

Coca-Cola: The soft drink maker reported a jump on fourth-quarter profit as strong sales in its overseas markets helped to offset continued weakness in soda sales at home. Stock (KO, Fortune 500)

MGIC: The Milwaukee-based mortgage insurer took a big hit in the fourth quarter as its business of reimbursing lenders when borrowers miss mortgage payments turned into a giant money pit. Stock (MTG)

Pfizer: A new study released at a conference shows that Pfizer's cancer drug Sutent may be linked to more instances of heart failure than previously thought. Stock (PFE, Fortune 500)

Waste Management: The top U.S. waste hauler says its fourth-quarter profit rose sharply on tax benefits and the sale of some operations. Stock (WMI, Fortune 500)

Applied Materials: The leading maker of equipment used by chipmakers, posted lower earnings that still beat forecasts. Its shares gained nearly 5% in after-hours trading. Stock (AMAT, Fortune 500)

Journal Communications: The publisher said December revenue from continuing operations slumped 23.1 percent, primarily hurt by an extra week in the prior year. Stock (JRN)