SPX needs to maintain a 61.8% or greater par-trend slope on the 20ma to prevent a negative divergence on the MACD in the coming 8 days. The 20ma's 61.8% par trend prices are plotted here, along with the resulting MACD. This is therefore the required price contour for maintaining 61.8% par trend price momo. Should price slack off on Monday and Tuesday (as plotted), coasting down into the momentum's air pocket so to speak, momentum will look ok (notice the MACD bounce at the 0 line) but price will set itself up for the need to climb much more steeply. Life will be easier for the bulls if they defend Monday and Tuesday, because Wednesday really lifts the bar high for continuation of the 20ma momentum.
Even at the 61.8% momo level, the 1-thru-20 day moving average summation looks to be weakening in the days ahead.
Here's a live 20ma partrend chart. The upper pink envelope line corresponds with the 61.8% par trend price contour plotted above.
http://stockcharts.com/c-sc/sc?s=$SPX&p=D&yr=0&mn=4&dy=0&i=p47931666360&a=135899840&r=6152.png
Trade safe, and have a good weekend.