The S&P 500 may not hit 3,200 by 2017 as predicted by Laszlo Birinyi, but the bull market may last another five years, QMA Associates' Ed Keon said Wednesday.
Birinyi made the call Tuesday on CNBC's "Fast Money: Halftime Report."
"I certainly hope Laszlo Birinyi is correct. The trouble is the fundamentals to get there. That's about 20 percent annualized return in a period where earnings growth is probably more likely to be mid-single digits," Keon told CNBC's "Squawk Box."
"So unless you get big increase in valuations, which are already at a little bit of a premium compared to historical averages, I just have a hard time making the math work to get to that big a gain in such a short period of time."
Read MoreA warmup act for Friday's job number
The S&P 500 ended Tuesday at 2,093, up nearly 1.7 percent for the year.
Still, in the midst of a "very unusual" economic expansion and bull market, the upward trend will last much longer than usual, said Keon, QMA's managing director.
"This one seems like it's going to last maybe another two, three, four, five years, both the economic expansion and the bull market. It's just that I think the pace of change is going to be relatively slow." he said, adding that GDP growth will likely remain between 2 and 3 percent.