Investors are abandoning the United States and flocking to Europe and Japan in search of better places for their money to increase in value.

The bull market has been underway for over six years in U.S. stocks, but there are concerns across the worlds’ largest economy that it's overdue for a correction.

"The fact they are pulling money out of U.S. equities seems to indicate some sort of fear about the future," says a senior analyst at Morningstar, Alina Lamy.

According to Morningstar, this year alone investors have withdrawn $64 billion from U.S. funds and put $158 billion of new money into international stock funds.

One major reason investors are running overseas is because American stocks have been essentially flat this year while European and Japanese stocks are scoring double-digit gains.

Japan's Nikkei has surged almost 19%, and Germany's DAX has shot up 17%.