RISING OIL: Stocks got off to a weak start. Oil climbed above $100 a barrel as the political turmoil in Egypt intensified, raising the risk of supply disruptions in the Suez Canal.

PORTUGUESE DEBT: Concerns that Europe's debt crisis was about to revive also weighed on markets. Portuguese government debt yields surged as the country's government teetered on the edge of collapse.

HIRING NEWS: The bad news was offset by brighter prospects for hiring in the U.S. Fewer people sought unemployment benefits last week and ADP, a payrolls processor, said businesses added more jobs last month than analysts had expected. The reports came as welcome news before the government's monthly survey of U.S. employment is released on Friday.