In perhaps the year's biggest flop, shares of King Digital Entertainment, the maker of mobile game "Candy Crush Saga," have tumbled more than 29 percent since going public in March.
"Remember how a few years ago, everyone had Angry Birds? That seems so 1998 now. These things run on a life cycle, and you need new things in the content pipeline all the time," said Jim O'Donnell, chief investment officer at San Francisco-based Forward, which has $5 billion in assets under management.
Some of the IPOs from late last year, including casual dining chain Potbelly, have also sunk. Potbelly is down 60 percent from its first-day close.
Given the underwhelming performance of several high-profile IPOs in recent months, some analysts worry investor appetite for risk is reaching unsustainable levels.
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Much of the influx of money-losing companies comes from one sector, biotechnology, where investors tolerate spotty track records in hopes of cashing in on lucrative payouts.
While some investors find their bets rewarded, as in the case of UltraGenyx Pharmaceutical, which is up 176 percent from its IPO price, others are disappointed. Three of the five worst performing IPOs of 2014 are in biotechnology.
"They're essentially looking at companies that don't have much in the way of revenue or profit and hoping to see that one big blockbuster drug approval or pharma company buyout," said Jeff Reeves, editor of InvestorPlace.com in Rockville, Maryland.
Yet even excluding biotech, IPOs look rich. Offer prices have been about 50 percent higher this year than the average from 2001 to 2013, even as median sales declined to $136.2 million from $187.3 million in the year before the companies go public, according to Ritter.
Experts say the stock market's gains, with the S&P 500 topping 2,000 for the first time last month, are somewhat responsible for the appetite for risk. And with the U.S. Federal Reserve keeping rates low, investors seeking growth are attracted to more untested companies.