A surge in private fundraising in 2015 helped technology startups steer clear of a painful initial-public-offering market. In 2016, they may not be able to avoid it.

A number of tech and Internet companies failed to reach their private valuations in their 2015 IPOs, while others later fell below their high-water marks in open trading, sending a chill through the growing crowd of private startups valued at $1 billion.

Big investors, concerned about the ability of IPOs to continue to generate hefty returns, in recent months have pulled out of funding rounds and marked down the value of their stakes in private startups.

Tougher private fundraising conditions could make it more difficult for startups to avoid the IPO market in 2016 if they need to raise money. And those deals, investors and bankers say, could face a chilly reception.

“We have definitely seen a shift in sentiment over the course of 2015, which has not only impacted valuations in the public markets, but has also made private raises more challenging,” said David Ludwig, head of technology, media and telecom equity capital markets at Goldman Sachs Group Inc. “The longer valuations stay at current levels, companies and their shareholders will realize this environment has become the new normal.”