I named it this because, as you can see from the ratio chart below (where each candle represents 1/4 of a year), price has now encroached into the last major bearish candle of Q3 of 2011, and has also fallen below the 60% Fibonacci retracement level taken from the 2009 lows of this ratio to its highs of 2014.
A hold below 80.00 could see the SPX plunge, particularly if this ratio drops and holds below 60.00. The declining Momentum indicator is hinting that further weakness is ahead for the SPX...as I mentioned here, with respect to the E-mini Futures Indices.
