Though it has struggled to stay in positive territory, the could climb 10 percent by the end of the year, widely followed bull Tom Lee contended Tuesday.
The index has fallen about 0.4 percent this year, and ended slightly lower on Tuesday. Still, seasonal strength and solid economic data could bring a year-end surge, said Lee, managing partner and head of research at Fundstrat Global Advisors.
"I know it's a stretch, but it's a seasonally good period. I think the U.S. data has been, for the most part, very good," he told CNBC's "Power Lunch."
Lee initially made his bullish double-digit growth projection on CNBC this month.
Lee shrugged off concerns that a possible Federal Reserve interest rate hike in December, combined with next year's presidential election, could derail markets. Market health is "dependent on the Fed not making a policy mistake," he said.
"I think a December hike under current conditions makes a lot of sense, and I think that would be very constructive under most market participants' views," Lee said.
He added that he expects stocks to continue grinding higher next year.