The end is nigh for the stock market boom, according to Albert Edwards, Societe Generale's notoriously bearish global strategist.
"A major market top may be forming in equities," warned Edwards in a report on Thursday. "Maybe it's time to stop dancing and sit this one out."
Edwards, who is known for his gloomy predictions about the global economy and markets, said equities had become increasingly out-of-sync with global economic realities such as disappointing economic data from " formerly reliably robust" China and Germany.
Both China and Germany posted weak manufacturing data this week, with German factory orders for August showing a particularly steep—and unexpected—decline.
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"Many market commentators are pointing out that U.S. inflation expectations have now slid to levels that previously triggered the Federal Reserve to enact quantitative easing, yet there seems to be absolutely no prospect of that occurring currently," he said.
Edwards also warned that this third-quarter earnings season, which unofficially kicked off with Alcoa's results on Wednesday, could prove "very tricky".
"U.S. companies have been playing their usual games in the run up to the reporting season by ramping down EPS (earnings per share) expectations so they can beat the numbers on the day," he said.
A higher-than-average number of companies have cut their EPS estimates over the third quarter, according to data provider Factset. EPS estimates have dropped 4.2 percent (to $29.06 from $30.33) during the quarter, above the average 3.2 percent decline seen over the past year, according to its data.
Edwards argued his concerns might soon be borne out in stock markets.
"Certainly you can feel the increasing nervousness in the market. Volatilities are definitely on the rise," he warned.
However, the three-year Wall Street rally is testament to the fact that Edwards does not always get it right.
In September 2012, he announced the U.S. was in recession and Wall Street would soon react, and warned of an "ultimate" death cross for the S&P 500—where the 50-month moving average falls below the 200-month moving average.
Instead the S&P 500 continued to rally, and has gained around 40 percent since Edwards' pronouncement.
"Am I calling a top? What's the point? As an uber-bear I am used to being called a stopped clock," Edwards wrote on Thursday.
But not everyone agrees with Edwards the "uber-bear". U.S. Trust Chief Investment Officer Chris Hyzy was sanguine about the U.S. economy when he spoke to CNBC on Wednesday.
"The private sector in the United States is the economic-momentum engine—albeit slower than we all want—to the rest of the world," he said. "If you actively manage money around that, you're going to outperform most of your peers."