Fred Wilson, a venture investor known for early bets on Twitter, Zynga and Coinbase, is predicting the high-profile IPOs expected in 2019 will price "well below the lofty expectations they have in mind right now."

Uber, Lyft and Airbnb are all preparing to go public this year — each at valuations in the tens of billions of dollars, buoyed by a decade of growth and fundraising. Late last year, Uber was reportedly fielding banking offers at a valuation of $120 billion.

Wilson, co-founder of Union Square Ventures, said in his annual predictions blog post that investors can expect those valuations to fall.

"Some of that will be because of weak equity markets in the U.S., but it is also true that most of the IPOs in 2018 also priced below the lofty 'going in' expectations of founders, managers, boards, and their bankers," Wilson said. "The public markets have been much more sanguine about value than the late stage private markets for a long time now."

Tech start-ups are largely immune to broader economic trends, Wilson said, minimizing the impact of a potential recession. But investors are likely to be more cautious in light of general market turmoil, he said.

"It would not surprise me to see total venture capital investments in 2019 decline from 2018," Wilson said. "And I think we will see financings take longer, diligence on new investments actually occur, and valuations to come under pressure for even the most attractive opportunities."

Wilson isn't the only skeptic in the VC world. According to the quarterly Silicon Valley Venture Capitalist Confidence Index, which was published on Monday, confidence fell sharply in the third quarter, dropping below its 15-year average. The survey of 26 Bay Area VCs took place in September, before the stock market's dramatic year-end drop.

WATCH: Here's what to expect for 2019 IPOs