Regardless of what you consider to be "the next big thing" in technology -- virtual reality, driverless cars, and/or the Internet of Things -- they all have one trait in common: artificial intelligence (AI). According to a report from management consultant McKinsey Global Institute, AI is expected to add $13 trillion to the global economy by 2030. For that reason, tech-focused growth investors can't ignore developments in AI.

With that in mind, we asked three Motley Fool contributors for AI-focused stocks to watch. Read on to find out why Amazon.com (NASDAQ:AMZN), Okta (NASDAQ:OKTA), and Accenture (NYSE:ACN) made the cut.

Robots on computers with network clouds above their heads.

Image source: Getty Images.

A multipronged AI approach

Chris Neiger (Amazon): This may not be the first company you think of when making a list of potential artificial intelligence investments, but there are at least three reasons investors should pay close attention to what it's doing with AI.

First, Amazon's popular Alexa assistant is allowing the company to use AI to learn more about its customers than ever before. Every time Echo smart-speaker users ask Alexa to tell them the weather, play a song, order a pizza, or buy more toothpaste, the company learns just a little bit more about what its users want. And it'll be using that data for years to sell more goods and services on its e-commerce website.

But that's not Amazon's only AI strategy. The company has also integrated AI services, like facial recognition and speech and text translation, to its cloud computing platform, Amazon Web Services (AWS). It is the No. 1 cloud computing platform and Amazon's biggest moneymaker, all of which means that as AI services become more important to developers, Amazon will likely benefit as AI and cloud computing become further entwined.

Finally, the hidden aspect of Amazon's AI strategy comes from how it uses machine learning, a type of artificial intelligence, to help the company decide what deals to offer, what products to promote, and how much demand a product will have. So the next time you're scrolling through Amazon, and you find the exact product you were looking for, thank AI for that.

For these reasons, any investors looking for a stock that is betting big on AI from multiple angles should have Amazon high on their list.

Picture of lock over binary code, signifying digital security.

Image source: Getty Images.

AI needs next-gen security

Jamal Carnette, CFA (Okta): The proliferation of artificial intelligence will require a significant ramp-up in compute and storage functions in short fashion. As a result, cloud computing and companies that provide access solutions will directly benefit from the technology. And this is where Okta comes in: It provides identity management solutions for both internal and third-party applications, giving companies an out-of-the-box solution to control who is on their networks.

Okta has found a receptive audience. In the first quarter, the company reported 50% year-over-year revenue growth, of which 94% is highly sticky subscription revenue. The company remains unprofitable under generally accepted accounting principles (GAAP). But free cash flow (cash from operations minus capital expenditures and software capitalization) grew to $13.2 million last quarter, up from a $1.6 million loss in the prior year's quarter.

More important is how Okta is growing revenue. In the first-quarter conference call, the company noted its net dollar retention for the trailing 12-month period was 119%. This is a fancy way of saying it grew revenue from existing customers via upgrades more than it lost via service downgrades and cancellations. That is, once companies have the service, they are more likely to upgrade than to leave. Look for Okta to continue to deepen relationships while adding new customers as AI takes hold.

It's time to take a closer look at this AI-fueled outsourcing titan

Anders Bylund (Accenture): The consulting and outsourcing giant formerly known as the business and technology division of Arthur Andersen is putting an amazing amount of work into AI research. The company is building AI into almost everything it does, from tailor-made app development and customer experience customization to data analytics or inventory management. Accenture is even working up wide-ranging frameworks to guide other companies to use AI technologies in a responsible way.

Simply put, AI tools make up the brains of Accenture's consulting services. And this business model has been firing on every cylinder in recent years. It's hard to find another company in the consulting industry that can match its sales and cash flow growth over the last five years. The one head-to-head rival that actually can match Accenture's recent growth spurt is the far smaller consultancy Cognizant (NASDAQ:CTSH), which is staring down long-term weakness in its two most important growth sectors.

So it's no surprise to see Accenture crushing its closest peers with a 146% share price gain in five years. The company reported solid third-quarter results at the end of June, setting the stage for accelerated sales growth and strong earnings in the fourth quarter. I think we'll see Accenture's AI-powered growth engines finding more traction in the coming years, starting in the next quarterly report. Hence, this would be a good time to open a position in this quietly skyrocketing giant.