Closely followed strategist Jim Paulsen told CNBC on Monday he's worried that economic data could stop supporting the stock market's bull run.
"The economy has been doing so good for so long now that even if it continues to do well, it won't any longer be a surprise," said Paulsen, chief investment strategist at Leuthold Group.
"Economic surprises I think are going to get as high as they're going to get," Paulsen told "Squawk Box." "We may see toward year end and the first quarter next year a pause in this market."
U.S. stocks futures were higher Monday as October continues to have an unusually positive month. The Dow and S&P 500 set record intraday highs on Friday. The Nasdaq posted a record closing high Friday and is up in 12 of the past 14 sessions.
Paulsen said the economy is in a "sweet spot," but he warned about a "chronic wall of worry" about the stock rally.
"The economy is still continuing to grow. We broke 6 percent unemployment three years ago. We broke 5 percent unemployment two years. And yet, we're still growing without aggravating inflation or interest rates," he said.
Also on "Squawk Box," AB Bernstein strategist Kathy Fisher said Wall Street could see a pullback but it won't last long.
"If we have a pullback — anything could happen anytime — the fundamentals, cash on balance sheet, all the things that we've talked about considering the health of corporations could be a stabilizing factor," she said.