The following monthly chart of the S&P 500 Index (SPX) simply shows the monthly closes from its inception.
January’s (2018) close of 2823.81 nearly tagged its long-term 140% trend-based Fibonacci extension level of 2836.
As of 2:03 pm ET today (Monday), its price is currently below its 1.27% Fibonacci extension level of 2625.
Failure to recapture and hold 2625 could see price eventually decline further to 2220 (its 1% Fib extension level), or lower to around 2100, due to a lack of major price consolidation support below its current price until then.
In my post of March 29, I had mentioned that:
Further equity weakness/volatility gauges to keep an eye on are detailed here.