If the market drops in the next few days, depending on the speed and distance of the decline we could be looking at the prelude to something volatile on the downside. Secondary to the trend-signal line I use Elliott wave analysis to assess the health of current price path of the market. EW is little too subjective to base trading signals off of, with the exception of Wave 5 signals.
One kind of Wave 5 signal is triggered at the end of 5 waves up or down. In this case, we count five waves and then look of a breakdown below the Wave 5 trend lines, accompanied by a momentum divergence. This pattern will trigger a counter trend move that retraces some or all (and possibly more) of the previous trend.
All of the discussion above is now embedded on these charts. The key takeaway is that we can assume Wave 5 is over when the lower trend-regression line is broken, about 21100. It seems a long way away, but in reality it is only one or two down days from current prices. When it is broken, the first target is 1,000 points lower. If so, a lot of money will be made on SPY puts and a decent return can be expected with inverse ETF's like QID and TZA. Below I've zoomed in on Wave 5. When it finally ends, we will be Short the market with significant downside potential.
Finally, unless and until the evidence that Wave 5 and the uptrend from last November is over the operative assumption is that the bull market is alive and well. Don't jump ship until it begins to take on water.