Tech stocks recently closed a strong quarter that left the Nasdaq index up 8% so far in 2019. That rally was supported by a brightening earnings outlook across much of the industry, but a few individual companies stand out as particularly attractive investments today.

Below, three contributors will look at why iRobot (IRBT -2.52%), Yandex (YNDX), and Blackberry (BB -2.73%) stocks are positioned for stellar growth.

An engineer working on a chip.

Image source: Getty Images.

No recharge needed

Demitri Kalogeropoulos (iRobot): Robotic cleaning device specialist iRobot is set to report its fiscal first-quarter earnings in late April, and there are plenty of reasons to expect good news in that announcement. The company in early February wrapped up a banner fiscal year that saw sales soar through the $1 billion mark from $884 million on strong demand for its latest lineup of Roomba products. Rising selling prices helped gross profit improve at a faster pace -- despite intense competition at the value side of the market.

These wins put iRobot in a great position to navigate challenges in fiscal 2019 that should include higher input prices and more competitive threats. And even that cost issue has a silver lining, since it is forcing management to make aggressive changes to its supply chain in order to build a much more efficient business.

In early 2018, CEO Colin Angle told investors that the next three years would likely be pivotal in determining which companies succeed over the long term as the robotic cleaning niche moves into the mainstream. The first of those years has to be considered a win for iRobot, and -- assuming it can maintain its innovation lead -- it's aiming for a second triumph in 2019.

Beating Google at its own game

Jamal Carnette, CFA (Yandex): There are only a few countries where Alphabet's Google doesn't claim the title as largest search engine by market share -- China and Russia being both notable examples. Russia is interesting because Google's not banned, but because Russian search engine Yandex boasts superior indexing and search capabilities for Cyrillic-derived languages.

Although Yandex is beating Alphabet in its home market, the company is wisely copying its U.S. competitor and becoming more of a tech-focused holding company. For example, Yandex has partnered with Uber for an on-demand taxi joint venture, has grown its Yandex Cloud service, and boasts one of the largest job-hunting sites with Yandex Jobs. These services are a play to deepen already existing relationships and further monetize its user base. It's working as analysts expect the company to report 31% top-line growth in 2019.

I'd be remiss if I didn't mention the risk of investing in a Russian company. The country is famous for state-owned enterprises and other shareholder-hostile precepts, but Yandex has been a refreshing exception in this regard. If anything, this is a slight positive in favor of the company because the Russian government has a vested interest in its success over Google.

Also, there is opportunity in Europe's largest Internet market. Although Russia lags the United States with a 76% internet penetration rate, it's mostly due to older generations: Internet use from ages 16-29 is at 99% and ages 30-54 at 88%. Look for Yandex to continue to post torrid growth rates as Russian millennials become a larger part of the economy.

BlackBerry is back in the black

Leo Sun (BlackBerry): BlackBerry's future looked bleak after it lost the smartphone market to iPhones and Android devices. However, the company underwent a radical transformation under CEO John Chen, who took the top job in 2013. Chen decided to phase out BlackBerry's ailing smartphone business and dramatically expand its enterprise software business.

That transformation initially caused painful revenue declines, but the software business gradually grew and offset the losses at its hardware business. BlackBerry also licensed its brand to the Chinese smartphone maker TCL to keep its brand alive and bolster the growth of its patent licensing business.

These efforts finally paid off last quarter, when BlackBerry posted its first quarter of positive sales growth in years. Its gross and operating margins expanded both sequentially and annually, and it remained firmly profitable by both non-GAAP and GAAP metrics.

BlackBerry expects its revenue to grow 23%-27% in fiscal 2020, which started on Feb. 29. It also expects operating margins at its core business (excluding its recent acquisition of Cylance) to remain steady year over year. It didn't provide any earnings guidance for the full year, but its margin outlook indicates that it will remain profitable.

The stock doesn't look cheap at about 50 times forward earnings. However, the company also posted 71% non-GAAP earnings growth in fiscal 2019, and that streak could continue this year.

If that happens, BlackBerry's valuation would look reasonable relative to its earnings growth. Its improving growth metrics and low enterprise value of $5 billion could also make it an attractive takeover target for larger enterprise software companies.