While the S&P has broken the trendline going back to 2011 (that is not good), it still remains above the 34ema and 89ema on the weekly chart, which is positive. If it breaks through those emas, I've drawn in major support lines that would be bounce zones.
Additionally, the biggest thing I am watching for is the crossover of the 34ema and 89ema. For 25 years, when the 34 crosses the 89, it has indicated a major bear market decline. Essentially, I think it would take us testing the August lows to elicit a cross. That would coincide with the testing of a massive head and shoulders neckline.