I am very bearish the SPX. Let me list some of my arguments below:
a. We have seen a massive and rapid run up in recent weeks (on top of an already long and 'hated' bull market).
b. The VIX (at 14 while i am typing this post) is really at a level that shows a level of complacency about this bull run. The highest it has been this year so far is 15! The last time it hit 20 was in Nov 2016. These are incredible numbers when you think about the inherent valuation risks in this market. It seems to me that not only are the markets over-priced, but are completely oblivious to the downside risks.
c. The upper and lower bands of the Bollinger Band in my chart have narrowed significantly. I use this as an easy to read sign of reduced volatility (which is confirmed by the stubbornly low VIX) and tells me that there is a move to the downside waiting to happen.