Please see my prior SPX posts.
Each sub wave subdivides into three waves. The final wave "5" appears to be under construction and could be truncated- meaning it won't exceed the 8/15/16 peak at 2193.
Wave "a" and "c" are usually equal. The bulls-eye target is 2182. Broader target zone 2181-2185.
9/30/16 is could be the target date for the secondary peak. That day is the end of the third quarter and has a . Markets occasionally turn on new or full moons.