Earlier this year, many top investors expected volatility to increase and stock market growth to slow, and while the market did tumble in late January, for the most part U.S. equities have been on another tear. The S&P 500 is up 7.45 percent year-to-date, and it's increased 12.43 percent since Feb. 8, when the market hit its low for the year.
Can these good gains continue into the fourth quarter? According to some experts, rising interest rates, geopolitics and slower earnings growth, among other things, could cause equity market growth to slow and even end America's almost 10-year bull run.
"We're in an uncomfortable bull market," said Sebastian Page, a Baltimore-based fund manager who oversees $300 billion of investments as T. Rowe Price's head of global multi-asset allocation.
Stocks have done well so far because of strong corporate earnings, due in part to tax reform and a recovery in energy prices, but that earnings growth, which has been in the 20 percent range, could decline dramatically in the latter part of the year, he said. He wouldn't be surprised to see earnings growth in the high single digits.
Why the decline? Because the global economy, which has been growing in unison for the last year, is decoupling again.
"Global growth is much less synchronized, the banking sector in Europe is quite fragile, and the dollar is appreciating, which doesn't help," he said. Since February the U.S. dollar has climbed by about 5.8 percent against a basket of other currencies.