Despite geopolitical uncertainty, uber-bull Jeremy Siegel still believes the market is going to continue to climb higher.
The widely followed Wharton School finance professor has been calling for the Dow Jones industrial average to hit 18,000 by year-end, and said he now thinks it could possibly hit 19,000.
The confluence of low inflation, still-low interest rates and one of the "best quarters" for earnings are ingredients "for continued upward movement on this bull market," he said Tuesday on CNBC's "Closing Bell."
Right now, the market is selling at 16.5 times 2014 earnings, Siegel noted. To get Dow 18,000, it would need to sell at 17.5 times earnings, "a very reasonable multiple given the interest rates." On top of that, in 2015, earnings are expected to increase another 6 percent to 10 percent.
He's also not too concerned about the uncertainties around the globe, like the conflicts in Ukraine and Gaza, affecting his thesis because the market has learned to live with them.
"We live in a world of uncertainty and bull markets actually climb the wall of worry," Siegel said. "When we see nothing in the future that can worry us at all, I'll get worried and I'll probably tell people to sell stocks."
As for the potential of rising interest rates derailing the market, Siegel is also unconcerned.
"I don't have the fear of that inflation at all now. I think the Fed was right. They said it was temporary factors and I think the markets are saying 'yes, we believe that that is the case,'" he said.
On Tuesday, economist Robert Shiller said the market might be getting too expensive. However, Siegel countered that Shiller factored the Great Recession into his model, and that caused a distortion.
"The decline in earnings that we saw during that crisis was the worst ever, even worse than the Great Depression of the '30s. So, is this something that we want to factor in the next few years of happening again? I don't think so," Siegel said.
He also defended his views, saying he was not biased toward being bullish. In fact, Siegel said he was bearish on stocks in 2000.
"I look at earnings and interest rates. Those are the ingredients of market prices and given those two levels right now, I think our bull market is still intact."
—By CNBC's Michelle Fox