I tend to agree with this. Per Fortune -I'm not superstitious, but the data is clear: More than a quarter of U.S. stock market drops greater than 10% since 1871 have happened in October - with October 1929 and October 1987 among the most famous.
And here we are again.
The year is already on track to be the worst for markets since the financial crisis. (Remember October 2008, anyone?) And there are other bad portents. China, the engine of emerging markets, is slowing - more statistical evidence of that today. We have a Fed chief who is untested (think Alan Greenspan in 1987), tech markets that still feel frothy, global geopolitics that are shaky, and a U.S. government is slowly careening toward another year-end, self-imposed fiscal crisis (yawn).
The counter, of course, is that the U.S. economy is in solid shape, with no hint of overheating. And it's worth remembering that the economy continued to grow for several years after the 1987 market debacle.
But economic cycles are real, and markets are telling us this one is entering its autumn. As Carl Icahn said yesterday, "I think the joyride is over." Prepare yourself.