The key to get from my articles is I use spikes in negative sentiment to add significantly to positions, then I take profits as the markets recover.

I believe it would be pure folly to use sentiment, or any indicator, to go all in or all out.

”....there are confident ones; they move from ninety-ten (90:10) in stocks-bonds to five-ninety-five (5:95) in stocks-bonds. That implies a degree of self-confidence bordering on hubris and self-deception. Over the decades, when both groups...have equal limited (!) ability to "time," the cautious chaps who alternate between sixty-five-thirty-five in stocks-bonds (65:35) and sixty-forty (60:40) are likely to end up with a superior risk-corrected total return score.”

[Paul Samuelson, "Journal of Portfolio Management," Fall 1994]

In my Newsletter’s Explore Portfolio, I currently use about two thirds in stocks with a ~5% variation based on seven different indicators listed on page 9 that include investor sentiment as one of the seven.