With elections in the U.S. and abroad looming, October may get "ugly," widely followed investor Dennis Gartman said Wednesday.
"October is going to be, I think, a spooky month," the editor and publisher of The Gartman Letter told CNBC's "Power Lunch."
"You have political circumstances, I think, that are going to make October an unbelievably volatile period of time. So, yes, you have earnings season beginning but I think it's the politics that will trump it all."
Not only is the U.S. presidential election on the horizon, but there are elections all across Europe — including in Spain and Austria, as well as an important referendum in Italy, Gartman noted.
On top of that, October has always been a "difficult" month, historically speaking, he said.
That doesn't have him talking about a bear market, however. Gartman said he still believes there is bull market, but he pointed out that such a market can still see a 5 or 10 percent decline.
When it comes to the market fundamentals, Gartman said it is all about central bank action around the globe.
"The overriding fundamental, whether it's the United States or Europe or Japan, is that the monetary authorities are continuing to be extraordinarily expansionary and they have no choice," he said.
"They've got themselves into a very difficult position and they can't back up. They're going to have to become even more expansionary than they have been. In the long run, in the end, that shall be inflationary, but right now it's not been."
— CNBC's Jackie O'Sullivan contributed to this report.