Stocks meandered at the start as uncertainty over the quarterly results this week kept investors from building positions.  Jittery investors, wanting to see more sings of an economic revival, sold off financial stocks after influential analyst Meredith Whitney downgraded shares of Goldman Sachs.  Whitney also lowered her earnings outlook for Bank of America and Citigroup.  Although late morning saw some strength, stocks struggled to stay afloat and ended the day mixed.   

Gains in commodity prices helped some mid-session buying in energy and material shares but the overall weakness in financial and healthcare stocks kept sentiment in check.  Shares of UnitedHealth Group Inc. (NYSE:UNH) and Aetna Inc. (NYSE:AET) fell more than 3% as the Senate Finance Committee approved an $829 billion plan to overhaul the U.S. health system.  Johnson & Johnson (NYSE:JNJ) fell 2.4% after the company reported revenue that was below the Street expectations.  However, the company reported higher