Even if you trade on fundamentals, it is a good idea to keep an eye on the charts to select your entry and exit points.
If we break down out of the short term trend (the hourly chart) then we would look to the SP daily and weekly charts to see where support might be found. Although things may seem obvious, they are rarely certain.
Keep in mind tomorrow is stock options expiry and the put buyers have been active. We are also going into a three day weekend in the States as Monday is a national holiday. There is significant worry about the Citi earnings report due out tomorrow.
Here is a snapshot of the SP500 emini futures at 10:30 AM.