The failure of the Super Committee to come up with budget cuts and the continuing problems with European debt spurred a sharp decline in stock markets as of this posting in the middle of the session. The S and P 500 index dropped sharply. There is concern about triggering the automatic cuts should the Super Committee fail to make a deal, a prospect that appears quite likely. The S and P has lost a total of 5.5 per cent in just four days.
The Dow Jones Index also declined to 11,507 or 2.5 per cent. In Canada stocks were down as well. See this article. The same worries as in the U.S. are factors in the decline. Stocks in Europe are also declining Rising costs of financing debts in France concern investors. Germany has reported that it is expanding at a lower rate. The rising costs of borrowing for many countries is leading to investors selling off more and more risky assets.
In the U.S. financial stocks are being hit very hard by worries that financial problems in Europe are going to impact U.S. banks as well. Some analysts claim that chances of a U.S. recession are increasing and others are predicting a bullish market. For much more detail see this Bloomberg article.