The year started off strong for technology-based initial public offerings, some of which got big first-day pops. Pinterest was offered at $19 a share and closed that day at $24.40 a share, a nice 28% gain. Zoom Video was offered at $36 a share and closed at $62 for a 72% gain. Of course, there's a big difference between an offer price that's for insiders and special investors and what a stock opens at for retail investors. Zoom, for instance, opened at $65 per share.

As the year wears on, the market's appetite for IPOs, tech especially, seems to be satiated. WeWork pulled its IPO after it had difficulty drumming up investor support, as did talent agency Endeavor.

Tech companies might struggle to find favor again now, but we'll take a look at the four biggest tech IPOs of 2019 so far, and look at three more still to come for which investors have high hopes.

Friends riding in an Uber

Ride-sharing apps were the biggest IPO draw earlier this year. Image source: Uber Technologies.

Peloton Interactive ($1.16 billion)

High-end stationary bicycle maker Peloton Interactive (NASDAQ:PTON) was also symptomatic of the disdain tech shares suddenly felt. It was offered at $29 a share, opened just above $27 a stub, and closed out its first day of trading at $25.76 for an 11% loss.

Still, it was one of the biggest tech IPOs of 2019, raising $1.16 billion, and Peloton seems as though it's growing fast, with 1.4 million accounts and half a million connected subscribers. It notes that 92% of all the interactive fitness equipment it's ever sold still has a $39 per month subscription attached to it. But its equipment is expensive and the economy may be heading toward recession.

The connected fitness market is a tough one to crack, as Fitbit has found out as it's now reportedly the subject of buyout rumors. Peloton may find it is similarly going nowhere.

Lyft ($2.34 billion)

Ride-sharing app Lyft (NASDAQ:LYFT) went public in late March at $72 a share and was another one of those tech IPOs that had a nice first-day bounce, opening at $87 a share. But it's all been downhill since then, and today shares trade at just over $39 each.

The market isn't convinced that the unprofitable unicorn was worth the valuation private equity investors assigned it, not when it's posting losses of nearly $1 billion, or $4.07 per share, and it faces regulatory hurdles that make it difficult to grow.

Slack Technologies ($4.56 billion)

Workplace collaboration platform Slack Technologies (NYSE:WORK) ought to be doing better than it is because of its industry-leading position and its ability to make employees more efficient. But after its June IPO -- well, it wasn't really an IPO, but rather a direct listing -- saw its stock begin trading at $38.50 per share, it's been a steady slide down to below $25 a stub.

Part of the concern is that pressure from Microsoft Teams is holding it back. There are fears the software giant could become an effective competitor over time. Analysts aren't so sure, but the downward pressure on Slack continues unabated.

Uber Technologies ($8.1 billion)

The biggest unicorn of them all, and one of the most anticipated IPOs at the time, Uber Technologies (NYSE:UBER) blew the doors off the IPO market with the world's biggest IPO of 2019, and seemed to defy the experience of other tech listings by actually trading higher for several months before giving up the ghost and plunging.

Uber is subject to many of the same concerns as Lyft, but it has added worries on its shoulders caused by internal turmoil and a desire to do more. It's expanded with side businesses like Uber Eats for food delivery and Uber Freight to connect carriers and shippers, while also trying to grow internationally. 

Yet it's also saddled with steep losses and a regulatory overhang, and its stock has suffered.

Is this the year?

While it doesn't seem as if any of the pending IPOs will come anywhere close to the valuation that Uber set, the three tech companies below have whetted investor appetites.

Airbnb

House sharing app Airbnb is one of those companies that's expected to go public every year but never does. It's often played coy about its plans, and earlier this year co-founder Nathan Blecharczyk told Business Insider, "We have already said that we are taking the steps to be ready to go public in 2019. That doesn't mean we will go public in 2019." This is one of those IPOs that investors should believe when they see it.

Palantir Technologies

Another perennial favorite of those speculating on companies that could go public anytime, data analytics firm Palantir Technologies is perhaps the one company that could rival Uber in size. The secretive firm counts the FBI, CIA, NSA, and other government agencies as customers, and has venture capitalist Peter Thiel, who founded PayPal, behind it.

Postmates

Food delivery start-up Postmates filed for an IPO way back in February, but with expectations it would launch by September, CEO Bastian Lehmann told a TechCrunch conference last week, "The reality is that we will IPO when we believe we find the right time for the business and the right time in the markets." The current market is too volatile, and the company is likely thinking about what occurred with Endeavor, Peloton, and WeWork.

It's clear the IPO market that was hot for any IPO, especially technology companies, has cooled considerably. If those suggesting we're heading toward a recession are right, the clock is ticking on a more opportune time to go public, as 2020 is likely to be even more volatile than this year.