The SPX from the bottom on 11/15/17 is near completion of an Elliott Five wave pattern. Wave "one" usually has a relationship to wave "five" Wave "1" of the pattern from 11/15/17 = 15.39 x 1.618 = 24.90 + 2577.62 - wave "4" = 2602.52
The supposed wave "5" appears to be an extended wave. Usually there is one extended in sub wave in any five wave pattern.