The US is currently riding a 5-day losing streak (the likes of which we haven't seen in awhile).
At 8:30 AM ET we get a very highly anticipated Non-Farm Payrolls report. This week we've seen a string of strong data, and interest rates have been rising, as markets begin to suspect that the Fed will soon pull the trigger on "tapering," a reduction in the pace of bond purchases through QE.
If today's jobs report is strong, and there's a notable drop in the unemployment rate, those fears could easily come true.
For a full preview of today's report, see here.