I do not take this post lightly. I was in NYC on September 11th, 2001. At the time I was trading for a hedge fund that was located in mid-town. I had many friends that died that day. My wife worked at the American Stock Exchange, which was literally across the street from the World Trade Center. She saw people jumping.
To me, it is clear that there were people who knew that the attacks were going to happen. Take a look at the action that occurred on the Thursday and Friday before Tuesday, September 11th. The downtrend that had started in May turned into capitulation. My guess is that were are some rich Saudi Arabians knew what was going to happen and became aggressive sellers.