I'm going to have a quick look today at the trendline and bollinger band backdrop to the retracement this week.
At the high last week a tentative rising channel has now been established from the October 2011 low. This is important because as long as this channel lasts the next obvious move will be to test rising channel support, currently in the 1575 area. It is also important because since the October 2011 low two large rising wedges have formed and broken up with targets in the 1930-65 area, but if this larger rising channel holds then both of those patterns and upside targets will be superseded. That's not to say that SPX wouldn't reach those levels later in any case, but those targets would no longer be active pattern targets.
There are two important trendline support levels on the way back to channel support, and the first is at the retest of broken resistance on the rising wedge from the June low at 1560. That is currently in the 1755-60 area and is a decent fit with the daily lower bollinger band, currently at 1754. If that level is taken out with confidence then that rising wedge target will be greatly weakened and a path would open up to the second trendline support level which is rising support from the 1560 low, currently in the 1690 area. SPX daily chart from October 2011:
On the shorter term daily chart the low yesterday tested the daily middle bollinger band and it's possible that this retracement could fail there. If so then we would now see a break back up towards the daily upper bollinger band, currently at 1820 but until we see a break back over the weekly pivot on ES at 1805.1 I'm expecting more downside, with the obvious target at the daily lower bollinger band, currently at 1754. SPX daily chart: