Normal Bullish Movements -- Powerful increase of price supported by volume over last 11 months. Decline of price on significantly lower volume starting January 2018. Flagpole --> Bull Flag. Touch of S3 level ($8500)on Camarilla pivot, this is the reversal level assuming trend stays bullish (decrease on lower volume). This is normal basing. MACD is still expanding as well.
Jan 2018 volume was 1/8th the volume of December alone; watching how the volume behaves in February will guide whether S3 will hold.
In other words: The decrease in price is not supported by volume; not much selling going on relatively speaking.