Yesterday was the second time S&P 500 tested 4100 level this month which could be a major resistance level at this time.
In addition, yesterday's sell off could be an indication that trades have less confidence in this rally.
Level to watch 4052 --- 4050
Reports to watch:
US:EIA Petroleum Status Report
10:30 AM ET
US:FOMC Announcement
2:00 PM ET
US:Fed Chair Press Conference
2:30 PM ET