I've read a lot of explanations for the post-election selloff. They all don't make much sense. Fiscal cliff is not news. No matter who won presidential elections, there would be fight in Congress about taxes and spending. Europe is in the news for two years already.
I think it was Sandy. It hit places where a lot of traders live. People needed money and had to sell something to get it. When you have thousands of people selling at the same time, you get market drop. And this drop is short lived, because they got enough money for initial expenses.
Well, I might be wrong.