After 30 years of watching this market, I have studied every form of chart-gazing, from Dow Theory to The Elliott Wave, and from Gann Angles to Three Peaks and a Domed House!

Some forms of technical analysis have endured for decades, like measuring the number of stocks advancing versus the number of stocks declining, during major market moves. Sometimes, that so-called advance/decline line weakens before a bull market comes to an end. That's known as a negative technical divergence and could foretell of a major correction, or even an impending bear market.