Stocks declined on Tuesday as wild weather stifled activity and led to low volume. By the end of the session, 1.4 billion shares had changed hands on the S&P 500, below its 10-day average volume of 2.1 billion. DSW (DSW) rose after topping profit estimates and expanding its margins over its fourth quarter. The shoe retailer earned 20 cents over the quarter, 4 cents higher than forecasts. Merchandise margins increased by 270 basis points to 40.4% at its namesake segment. AstraZeneca (AZN - Get Report) climbed in afternoon trading after publishing positive data on its late-stage ovarian cancer study. Results from a Phase 3 clinical trial resulted in improvement in progression-free survival compared to a placebo. AirMethods (AIRM) agreed to an acquisition by American Securities. The latter offered $43 a share in an all-cash deal with a total value of around $2.5 billion.