A close below would be bearish and only the 2nd close below in 2018 and 3rd close since March 2016.
With 2 hours of trading to go, the S&P is trading right around the 200 day MA at 2765.94.
The index is currently down about -19.49 points at 2766.19. The high reached 2795.14. The low reached 2745.46.
A close below the 200 day MA would be the first close below since early April 2nd 2018, and bearish.
There were only one close below the 200 day MA in 2018 and only two closes below going back to March 2016 (the other one was on June 27, 2016). The price traded below the 200 day MA on 6 trading days before today (today is the 7th).