I really don't know what cause this decline. It could be from bad NFP report or the ongoing fear of taper.
US Dollar devalues against all major currencies.
If bad NFP report is cause: Equity increses and Currency decreases.
If fear of taper is cause: equity fall down and currency soar up.
However, the fact is opposite.
No matter what what caused that decline. I think SP500 after pierced the key support I show on the chart, it will test next support 1810.55.