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Prepare for a swoon, but not because it’s September

Stocks have, on average, swooned in September, wiping out gains in the last 20, 50 and 100 years. Will history repeat itself this September?

Big institutional investors such as Blackstone and Wells Capital Management have raised concerns that this summer rally could grind to a halt. The Leuthold Group's Doug Ramsey told The Wall Street Journal that an 8% to 10% market correction was coming and "there's a good chance that it would wipe out all the gains for the year."

Yahoo Finance's Aaron Task says investors should be worried because the "S&P has gone up like a scalded cat" but he doesn't expect markets will drop simply because of the calendar year. "There will be some catalyst for a selloff," he argues in the video above. The S&P 500 Index has gained a little more than 8% since the beginning of the year and is up 94% over the past five years.

What catalyst could bring down the markets? Task isn't sure, but he doubts current geopolitical events or a shift in U.S. monetary policy will be the reasons. He says investors have largely shrugged off rising tensions between Russia and Ukraine and the fighting in Israel and Gaza this summer.

Related: Why investors shouldn't ignore geopolitics

Last month Fed Chair Janet Yellen "poured cold water" over rumors that an interest rate hike will happen early next year, notes Task, a bullish sign for investors. Moreover, inflation is still running below the Federal Reserve's 2% target and near-zero rates have not put pressure on wages.

Related: The Fed should ‘give money directly to the people’: Economist

Are you expecting a market selloff? Tell us how you're protecting your portfolio in the comment section below!

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