It's been a rough year for investors, and the volatility has been particularly pronounced for some of the stocks that went public in 2018. Many once-promising stocks have faltered, and in most cases, buckled below their IPO price tags. A whopping 117 of the 191 companies that have gone public on stateside exchanges -- as measured by newbie tracker IPOScoop -- are broken IPOs as of Wednesday's close.

Some of the broken rookies will stay that way, but a few of them have catalysts in place to bounce back in 2019. iQiyi (IQ -3.90%), Sonos (SONO -2.03%), and Tencent Music Entertainment (TME -1.56%) have the right ingredients to win back investors in the year ahead. Let's take a closer look.

Interior of a personal iQiyi theater that can be rented out for private iQiyi-streamed screenings.

Image source: iQiyi.

iQiyi -- down 13% 

China's leading video-streaming service has had a roller-coaster ride in its first nine months of trading. The stock went public at $18 in late March, traded as high as $46.23 three months later, only to give it all back -- and then some -- to find the shares currently trading in the mid-teens.

iQiyi is living up to heady growth expectations. Revenue soared 48% in its latest quarter. It's doing a great job of converting ad-supporting freeloaders into paying users, as its base of premium subscribers has surged 89% over the past year to hit 80.7 million. Guidance calls for revenue to climb 43% to 49% in the current quarter, and analysts see the pace decelerating to 33% for all of 2019. 

Losses are mounting for iQiyi, but it's just not at a point where it can measured by its profitability. Expanding quickly and building up its content library is what will deliver the huge audience that will make it a bigger force down the road. Investors have just been shying away from Chinese growth stocks since the trade tariff tensions began, even though one would think that a streaming entertainment service would be one of the last industries impacted by a trade dispute. If you think the leading global premium streaming service is a bargain at 8.2 times trailing revenue, you're going to love the opportunity to grab iQiyi at a 3.1 multiple. 

Sonos -- down 30%

The stock in the biggest hole among the three names here is Sonos. The shares have lost nearly a third of their value since going public at $15 over the summer. The pioneer of wireless speakers has been smacked around for the lumpiness in its first two quarterly reports as a public company. 

Sonos took a hit after posting a 7% decline in revenue for its fiscal third quarter, even though the slide was explicitly spelled out in its prospectus. Sonos had put out its first home theater sound base a year earlier, propping up the prior year's third-quarter performance with the big-ticket item. The market initially liked its fiscal fourth-quarter numbers, but the 27% top-line surge was eventually offset by guidance calling for a mere 3% to 6% advance in revenue for the current quarter. 

Lumpiness is going to be a constant here. Sonos' results are influenced by product rollouts. Investors are concerned about all of the tech giants putting out subsidized smart speakers, but Sonos should continue to carve out a niche in the multiroom wireless speaker market it created. It sees 10% to 12% in revenue growth for the entire new fiscal year, pushing its impressive streak of growth on an annual basis to 14 years. 

Tencent Music -- down 6%

iQiyi isn't the only spinoff of a Chinese dot-com giant that has been dismissed by investors. Tencent figured that offering its fast-growing online music subsidiary would be music to the market's ears. It wanted to take Tencent Music public at $13 to $15, ultimately settling for the low end of that range in last week's debut. The shares did close at $14 on its first day of trading, only to buckle below $13 after falling in four of the five subsequent trading days. 

Tencent Music checks off all of the boxes that growth investors crave. It dominates its market, with more than 800 million monthly active users, controlling roughly 75% of China's streaming-music market across all of its subsidiaries. It's sticky, as daily active users spend an average of over 70 minutes a day on the service. Revenue has soared 84% through the first nine months of this year, and profitability has more than tripled. Yes, Tencent Music is generating a chunky  profit in an industry where licensing costs can eat away at the bottom line. 

The key to Tencent Music's monster growth and refreshing profitability is that less than 30% of its revenue is coming from its music services directly. More than two-thirds of the revenue is being generated by its music-centric social entertainment services, largely virtual gifts that users can send in appreciation of karaoke or live performances. Tencent Music would've been a hot debutante a year ago, and now this monster growth stock has faded out in just a week. Things will change when market sentiment turns the beat around.