Here I've done some non-linear trend analysis on the SPY ETF. The upward sloping curves represent the long term trading range with compounding considered. Since the 2009 lows SPY has rallied vigorously from the bottom of this range (light blue) to the top end of this range (neon green). The linear trend of this rally is roughly equal to the tangent of this neon green curve at the first Elliott point and will hold as support if the bull trend remains intact. I believe there is one last secular wave toward $350 before any significant drop, based on this chart, and that prudent buying in the current price range is ideal. The inverted curves suggest some potential draw-down scenarios. The orange scenario basically represents the end of the US financial markets as we know them. A retest of the 2002 and 2009 lows would be catastrophic, to say the least, and investor confidence may never recover from such a thrashing. The pink scenario is the likely price action if October 2018 marks the top of this secular bull. In this case, heavy support should be found around the 2016 lows of $180. The current market environment could break the levee and put this price in play over the next few months. The black draw-down curve is what could happen after a wave 5 rally. Support after this run would be at one of the many upward sloping curves and will be more determined by the length of the draw-down period and any support pivots built along the way.