Last night Obama made a speech laying out the case for attacking Syria.
But he said that he had asked Congress to postpone a vote authorizing such a strike while a diplomatic solution was being found.
As we noted at the time, various equity markets around the world caught a spike on the news.
Check out what happened to oil futures just before 9:15 ET (when his talks concluded). They instantly dropped.
Eventually oil prices gained again, but this is a nice example of how headlines and sentiment can combine to create quick reactions.