For a technical picture I turn to Permabear Doomster for some long term perspective. The market appears over stretched long term with no meaning full correction since 2011. It has broken down below 1840 after making a series of lower highs between 1940 and 2135. Market internals have broken down and bearish divergences in market indicators implies downside in the upcoming months. Currently a rally has occurred from the lows near 1800 which may not hold in the future:
Support - 2080
Resistance - 2135
All in all the risk reward trade for the long term appears to be on the down side.