The stock market's climb to repeated record highs in recent weeks has some market participants concerned that a major correction may be coming.

Renowned activist investor Carl Icahn apparently is one of them.

"In my mind, it is time to be cautious about the U.S. stock market," he told Reuters. "While we are having a great year, I am being very selective about the companies I purchase."

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The S&P 500 index has generated a total return of 6.3 percent so far this year. It closed Thursday at 1,964.68, approximately 1 percent below its all-time peak.

Icahn has pushed discount retailer Family Dollar Stores to put itself up for sale. The company announced Thursday that its profit dropped by one-third in the latest quarter.

"The leadership, to say the least, is questionable at Family Dollar, and it's been that way for many years," Icahn said. "[CEO] Howard [Levine] might be a nice guy, but he is far from the right leader for Family Dollar."

Icahn isn't the only one nervous about stocks. Jeff Reeves, editor of InvestorPlace.com, lists seven reasons why a 10 to 15 percent correction may happen in the next few months.

Basically, there's a "disconnect between fundamentals and expectations," he writes in an article for MarketWatch.

1. "Earnings look shaky." Earnings estimates for the second quarter already have been reduced, Reeves notes.

2. "Warmer weather isn't helping." Cold weather was blamed for the first quarter's GDP and earnings weakness. But warmer weather can't make up for all of that.

3. "Housing trouble." The industry is looking shaky, with inventories rising.

4. "Price inflation, but not wage inflation." Consumer price increases are accelerating, while wages are stagnant.

5. "Global unrest." There's turmoil in Ukraine, Iraq and Israel for starters.

6. "Interest rate risk." The Federal Reserve may raise rates earlier than many expect.

7. "The everything bubble. Valuations are stretched [in asset markets] across the board, and that just adds to the fear that many investors feel," Reeves writes.

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