As for the Fed meeting next week, he expects it to stay the course and continue to taper its bond buying program. "I think the Fed's been pretty explicit about what it's doing. I don't think that's where the volatility comes from," he said.
Ward McCarthy, chief financial economist at Jefferies, said he expects the Fed to cut its growth forecast next week to a range of possibly 2.6 to 2.8 percent or lower for 2014, from 2.8 to 3 percent. He also expects the Fed to cut its 2014 target range for unemployment to 6.3 percent, from 6.1 percent, since unemployment is already at 6.3 percent.
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"It will be an interesting meeting and an interesting policy statement," he said.
Traders already expect some volatility around that meeting, and the Fed's comments on the economy will be closely watched. One of the catalysts keeping stocks moving higher is the belief the economy is improving and growth is picking up so any big negative surprise in economic data could also create volatility.
"I'm thinking the second half of the year will probably be more volatile than the first half," Doll said "The data I think will look better. I think the leading economic indicators have been looking a bit better. I think the jobs numbers have been looking a bit better. We're not going to look back at 2014 and say 'remember how good the economy was.' I just think it's notably better than the first half of the year."
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Doll said the main risk to the market is that the economy does not grow enough. As a result earnings would not improve enough to support market valuations. He said an inflation scare is another risk for the market, but he doesn't see inflation at problem levels though it could pick up slightly.