When the credit crunch hit in full force in the fall of 2008, investors got out of stocks as fast as they could and bought government securities instead. Two years later, they're still buying government bonds.

Longer-term Treasury bonds have returned 2.1 percent so far this year, while the Dow Jones is down 2 percent.

Some investors believe bonds will keep doing well, because the economy is weak, and that won't help stocks. But others said bonds are not a good long-term investment and they believe stocks will do better over time.

"In the long run we don't think you'll make a good return" in government bonds, said Mark Phelps, CEO of money manager W.P. Stewart & Co., citing the low yields.

"To put all in Treasuries, looks like a mistake to us," Phelps said, whose firm manages $1.5 billion. But he adds, "I would have said that at the beginning of the year, and I would have been wrong."