Investing in the stock market is the surest way to build long-term wealth. Diversification among companies, industries, and types of securities is the key to ensuring that investors can reach their goals. Technology stocks can provide a boost to returns, as these companies are often on the cutting edge, making groundbreaking discoveries that change our everyday lives.

With that in mind, we asked three Motley Fool investors to choose top companies they believe to be offering compelling opportunities in the tech sector. They provided convincing arguments for Netflix, Inc. (NASDAQ:NFLX), Activision Blizzard, Inc. (NASDAQ:ATVI), and Facebook, Inc. (NASDAQ:FB)

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A global opportunity

Danny Vena (Netflix): Investors in Netflix have been amply rewarded for their ongoing faith that the company can continue to conquer the world. Thus far, Netflix has lived up to those high expectations, with the stock gaining over 100% in the last year alone. While that might sound like a reason not to invest now, the company's global opportunity remains enormous and the stock shows no signs of slowing.

Since early 2016, when Netflix revealed that it had added 130 countries to its streaming rolls for a whopping total of 190 countries worldwide, the streaming giant has moved with speed and confidence to achieve its lofty goal. With an estimated total addressable market of 524 million and growing, the company is just getting started.

Netflix said it will be spending between $7.5 billion and $8 billion on content in 2018, creating 700 new original series and 80 feature films, as well as a plethora of licensed programs. Its original-content strategy appears to be paying off, as the company added nearly 24 million streaming members to its ranks last year, an increase of 25% year over year, and that figure now tops 125 million. The influx of new subscribers boosted its financial performance as well, increasing its revenue by 32% to $11.7 billion last year, while net income nearly tripled to $560 million.

Entrance to a glass-front building with the Netflix logo above the door

Image source: Netflix.

That growth is accelerating thus far in 2018. In its first quarter, Netflix reported revenue of $3.7 billion, up 40% year over year, and net income increased to $290 million, up 63% over the prior-year quarter. Even as the company continues to invest vast sums of money in content, its operating margin continues to grow, achieving 12.1% last quarter, up from just 9.7% in the same period last year.

Even in light of its stellar growth, the opportunity remains vast. I think investors should buy Netflix right now, as the company is still in the early stages of its worldwide expansion.

Gaming the recent pullback

Steve Symington (Activision Blizzard): With eight $1 billion-plus franchises in its enviable portfolio -- think wildly popular titles like Call of Duty, Overwatch, Destiny, and World of Warcraft -- it's no mystery that Activision Blizzard is a leader in the burgeoning video game space. Activision also enjoys a commanding lead in the mobile gaming market through its $5.9 billion acquisition of Candy Crush-maker King Digital in late 2015.

And it doesn't just make money from the initial sale of its games. Many of its titles enjoy a fervent base of paying monthly subscribers, and in-game content sales exceeded $1 billion last quarter alone. That's not to mention the promise of management's plans to implement more in-game advertising to generate incremental revenue.

A female gamer and her team participate in an esports tournament.

Image source: Getty Images.

What's more, with the launch of its new Overwatch League earlier this year, Activision is poised to benefit from the unstoppable rise of esports. According to SuperData Research, the esports market is expected to attract nearly 300 million unique viewers this year, and should exceed $2 billion in revenue by 2021.

With the stock trading around 15% below its 52-week high amid a broader pullback in tech stocks in recent weeks, I think now is a great time to open or add to a position in Activision Blizzard.

The scandal is being forgotten

Jeremy Bowman (Facebook): Facebook shares have already begun recovering from the Cambridge Analytica scandal. The stock bottomed out at $149 amid revelations that Facebook's data was co-opted against its rules to influence the election, which led to a whirlwind of concerns about privacy and how the company handles user data.

CEO Mark Zuckerberg went before Congress last week to answer questions from legislators and defend the company, and investors responded to his performance favorably, sending the stock higher. As of this writing, the stock is back up at $168, but is still trading significantly below its all-time high of $195, where it was before the scandal broke.

Headshot of Facebook CEO Mark Zuckerberg

Facebook CEO Mark Zuckerberg. Image source: Facebook.

It's starting to look like the social network will emerge from the incident unscathed. On Google Trends, searches for terms like "Cambridge Analytica" and "delete Facebook" have declined sharply since peaking in March. More importantly, Facebook has said that there's been no significant effect on advertiser behavior. At a Wall Street Journal forum, Facebook vice president of global marketing solutions Carolyn Everson said users mostly hadn't changed their privacy settings, and that the company doesn't expect any noticeable impact to revenue.

Moreover, even if Congress decided to impose regulations in the aftermath of the scandal, it would likely squeeze Facebook's weaker rivals like Twitter and Snap as well, further strengthening the company's monopolylike dominance of social media.

Take advantage of the sale price before the discount's gone. I'd expect another strong earnings report from the social-media giant when it delivers first-quarter results later this month.

Danny Vena owns shares of Activision Blizzard, Facebook, and Netflix. Jeremy Bowman owns shares of Facebook and Netflix. Steve Symington has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Activision Blizzard, Facebook, Netflix, and Twitter. The Motley Fool has a disclosure policy.