After years of flying high, the stocks of big technology companies from Facebook to Apple are either tumbling or struggling to maintain their altitude in 2018. But while the big players may be off to a rough start, a number of smaller tech stocks have been making strong gains, including ShotSpotter Inc. (SSTI), R1 RCM Inc. (RCM), Casa Systems Inc. (CASA), Twilio Inc. (TWLO) and Momo Inc. (MOMO). On average, these five stocks are up 78% so far this year, compared to the 2% return of the Nasdaq 100.

ShotSpotter leads this group of outperformers with a year to date return of 124.8%, as of the close of trading on Monday; R1 RCM is up 72.1% for the year; Casa is up 67.8%; Twilio is up 75.4%; and Momo is up 49.4%. These companies may have something to offer and at the very least, their “durable growth in a challenging stock market environment” makes it worth giving them a look, according to MarketWatch. (To read more, see: 5 Tech Stocks’ New Growth Engine.)

ShotSpotter

This young but fast-growing company designs and manufactures gunfire detection and location technology, which utilizes surveillance infrastructure to alert local law enforcement of gun shots in the area.

While the company has yet to turn a profit, revenue is expected to grow 35% this year and at least that much next year as well, and is likely to post positive earnings within a year, according to MarketWatch.

R1 RCM

This software and services firm provides health-care companies with “revenue cycle management,” aiding hospitals and doctors with complex medical-billing processes. Saving time on these processes means being able to serve more patients.

While the company is still burning through cash to boost growth, it claims that it will earn consistent profits and bring in over $1 billion in sales by next year.

Casa Systems

Another young company, Casa specializes in helping data network operators provide better data services to their clients, an important service in a world that is becoming increasingly reliant on being able to access data.

The company projects revenue to grow at 11% this year and 19% for the 2019 fiscal year. With demand for data only becoming bigger, it’s hard not to see how Casa won’t deliver.

Twilio

This cloud-communications provider is turning things around after its shares lost more than half their value after the big run-up following its 2016 IPO. Since touching below $25 early this year, its shares have picked up enormous momentum partly owing to new products such as its Flex contact center.

With more new products set to launch this year, investors have good reason to be optimistic about the future, according to MarketWatch. (To read more, see: Twilio Stock Breaks Out to Retest Prior Highs.)

Momo

This China-based tech company provides messaging services, including an app similar to Tinder that allows users to interact with both friends and nearby strangers using their smartphones. Such applications will benefit from China’s urbanization trend.

Revenues are expected to rise 37% this year with earnings spiking 29%, and that strong performance is likely to continue next year with revenue and earnings growth of 25% and 24%, respectively.