The stock market just hit a milestone that some market watchers s𓆏ay is a sure sign of more gains ahead. 

Stocks on the New York Stock Exchange (NYSE) on Thursday completed a 澳洲幸运5官方开奖结果体彩网:Zweig Breadth Thrust (ZBT), which is realized when the share of rising stocks increases from a moving average of less than 40% to more than 61.5% within a 10-day period. The rare occurrence, which has only been seen 19 times in the last 80 years, is considered a sign of increasing market momentum driven by broad bullish 澳洲幸运5官方开奖结果体彩网:sentiment. 

"This signal has been 100% accurate since WWII, with the 澳洲幸运5官方开奖结果体彩网:S&P 500 higher 6- and 12-months later every single time," according to Ryan Detrick, chief market strategist at Carson Group. Looking at the last 19 ZBT signals, the S&P 500 has averaged a 6-month return of 14.8% and a 1-year return of𒊎 23.4%, according to Detrick. 

Stocks have rebounded from their 澳洲幸运5官方开奖结果体彩网:"Liberation Day" slump amid optimism that the White House is 澳洲幸运5官方开奖结果体彩网:eager to defuse tensions with China, which the administration has slapped with tariffs totaling 145% this year. The S&P 500 was 澳洲幸运5官方开奖结果体彩网:up slightly on Friday af💫ter rising more than 1.5% in each of the last three sessions. 

ZBT's Long-Term Record Is Spottier

Not everyone is sold on ZBT’s predictive power. 澳洲幸运5官方开奖结果体彩网:Technical analyst Tom McClellan, in 2015, examined Breadth Thrusts between 1929 💮and 1934 and found them to be much𓆉 less reliable bullish signals. 

The first signal in this period came in November 1930, and it did precede a strong upswing. "But its bullish effect petered out after just a few months, and the bear market was back on," McClellan wrote. Over the next two years, four more Breadth Thrusts failed to break the 澳洲幸运5官方开奖结果体彩网:bear market. 

"It was only in April 1933 that there was finally a good signal that led to follow-on buying," McClellan said. But that signal was followed by two more in 1934 that didn’t come to much. 

McClellan was writing in 2015, when a ZBT signal was triggered just months after stocks hit a record high. "I cannot offer much in the way of optimistic commentary about this current ZBT signal," McClellan wrote, "especially since it has occurred at a point that appears to be the early stage of a new 澳洲幸运5官方开奖结果体彩网:downtrend."

Stocks did rise after that ZBT signal, but it was one of the weakest ZBT rallies on record, with the S&P 500 up just 1.4% and 7% over the next 6 and 12 months, respectively, according to Detrick's data.