I follow a CFA from Charles Schwab, who uses this signal to establish negative or positive sentiment. To notice how it worked in the past, I have added the S&P500 trend line.
The idea is as follows: When the upper Bollinger Band (with a 50 period and 1 standard deviation) on the VIX turns higher, that is a bearish sign, and when it turns lower, the SPY tends to rally.
----------- Also, today January 28th, we had a Hindenburg Omen flash.