Atlantic Trust CIO David Donabedian tells CNBC's "Power Lunch" on Monday he's seeing an improvement in most asset classes.
"The U.S. economy is a bit uneven, but we're in a sustainable long-term economic expansion. As long as that is the case, we will be in a long-term bull market," Donabedian said.
He believes the impact of a slowdown in China on U.S. economic growth is fairly small.
"The bull market will continue into 2016 as long as you have decent economic expansion and monetary policy that isn't tight," Donabedian said.
The Dow and S&P are modestly higher during trading.