The could very well rise another 10 percent by year-end, Wharton School of Business finance professor Jeremy Siegel said Monday.
Siegel reiterated his call that the index would finish the year between 16,000 and 17,000. "It can happen. That's about a 10 percent increase from now, and certainly it's [a] possibility."
He told CNBC's "Fast Money" that he saw his bullish call as a cakewalk.
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"Seventeen is going to be an easy target next year to reach and surpass, in my opinion," Siegel said. "I don't know if we're going to quite get there by Dec. 31, but near."
A softening in small- and mid-cap stocks doesn't concern him, he said.
"The breadth of the market has been very, very strong," Siegel said. "Yes, there's a little setback in the Russell, and I do look at that as a short-run indicator—but when I take a look at stable interest rates, 2.50 to 2.60, oil down … which I think is very, very bullish for the stock market.
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Siegel was also positive about fourth-quarter results.
"Earnings are going to be good, up 10 percent this year. Fourth-quarter comparisons are going to be very good," he said. "Last year, we had a lot of markdowns in the fourth quarter because of the pension funds. Interest rates are now higher. There's actually going to be some accretions to those funds going into the fourth quarter.
"Bottom line, I've been saying at these levels of interest rates, you know, 18, 19 is the historical valuation of the market. We are still below that today."
(Read more: Dow could rise 10 percent or more in 2014: Siegel)
The idea that the Federal Reserve would reduce its $85 billion-a-month asset-purchasing program, known as quantitative easing, also didn't deter Siegel from the bullish prediction.
"I'm one of these people that don't think this whole rally is due to QE," he said. "My feeling is there are earnings behind this rally and an extremely favorable interest rate climate, and those are the two major ingredients for stocks. I don't need an extra push from QE to get prices at the levels now."
Stocks are still the best play for investors, according to Siegel.
"Where are people going to put their money? Money market funds are still at zero," he said. "It's still the place to go."