This is not the year startups rush to go public. Far from it: Stock market debuts have all but bottomed out. But the lull won't last, says one IPO expert.

From January to May, there were 31 initial public offerings, according to Barron's. Over the same period the prior year, there were 69, and in 2014 that same five-month period saw 115 IPOs.

Earnst & Young Americas IPO markets leader Jackie Kelley says there will be a big-time bounce back in 2017, which the firm's next quarterly global IPO trends report will flesh out. The latest report will be available June 29. 

"We're building a really robust pipeline next year, is what's happening," she says, clarifying that "we" refers to U.S. markets. She expects IPO activity comparable to 2014 levels.

Kelley predicts companies will start filing late year for IPOs in March and April of 2017, and says many of those filing are likely to be "unicorn startups," or those valued at more than $1 billion. She didn't share a range for how many IPOs she expects.

As for this year, Ernst & Young is advising startups it works with not to IPO if they haven't already, she says. "I think we went into this year expecting that it would be a slow year. We had a lot of headwinds going in."

The first half of the year brought global economic issues like a downturn in the Chinese stock market, plus a correction in startup valuations in the U.S. Summer tends to be slow for IPOs, adds Kelley, and after summer is the 2016 U.S. presidential election. "All this uncertainty doesn't make for a good time to go public."

The larger view, she says, is a coming return to normalcy after two to three years of skepticism about the wisdom of going public and a disproportionate and ahistoric preference to stay private as long as possible.