December's uptick in consumer confidence suggests that the bull market in the United States can still extend far into the future, albeit with a few bumps, Nuveen's chief equity strategist, Bob Doll, told CNBC on Tuesday.
"We've spent this entire bull market with nobody believing it. The caution, the concern, 'The next downturn's going to kill me,' and now we're beginning to have people feel a little bit better. That's always a good sign, and bull markets don't end until you get that euphoria," Doll said.
"We're nowhere near that. We may be moving from cautiousness to optimism, but euphoria's down the line somewhere," he told "Squawk on the Street."
Doll said that confidence always helps the economy do better, though too much optimism could pose a problem if the cause for that isn't justified.
"If people feel better about life, no matter what policy is, they spend a little more money," he said. "The question is, is the confidence coming back so fast that no matter what happens, the markets can't deliver, the economy can't deliver? We'll see."
But even if pumped-up confidence does pose a threat, signs of growth ticking up in the United States in 2017 could provide a basis for that positive outlook, Doll contended.
"I think as long as the U.S. growth expectations move higher, as long as the dollar is moving higher, this says the U.S. is where it's happening. Stronger growth differential, the interest rate differential, I think this points to further strength in the U.S. versus the rest of the world," he said.
"We're completing the seventh year in a row where the U.S. has led, so it won't happen forever, but I think the signs are still there, at least early in the year," Doll added.