I find the rising wedge formation in the shorter term a very reliable indicator of a strong sell-off ahead.
In this case the S&P 500 is forming a much longer-term rising wedge that will more than likely result in a sell-off (major?) nearer the top of the long-term uptrend channel.
The Fibonacci retracements indicate a weakening trading cycle, with the second cycle close to a 73.6% retracement, compared to the earlier, healthy 38.2% retracement.
Nothing too complicated here.