Past ~1.5yrs the ratio between SPX500 and gold (XAUUSD) has followed a channel defined by a 3pt trend line on top and its parallel 2pt trend line below.
Currently close to its upper limit. The past 2 peaks were "resolved" by a short term increase in the price of gold, thereby lowering the ratio (increasing the denominator).
Alternative resolutions include:, SPY can drop. or, they both drop but SPY drop faster.
Also, see RSI of the ratio with long signal for Gold and short for SPY