Since the breakout failure from the end of 2015, AMZN broke down from its first support area of 640 and now is challenging its first major uptrend line on the weekly chart. The next level of support is the somewhere around 540 to 535, which is the 61.8% fib retracement and also the retrace from top of the extension (Please see the top green line). There should be room for for another 30 points on the downside.