There are plenty of reasons to consider investing in artificial intelligence (AI). For one, it will likely transform the transportation industry over the next two decades through driverless cars. AI is also being used to help speed along drug research and even improve detection of life-threatening illnesses.

Additionally, developing smart AI computer systems that can analyze data faster and apply their insights more efficiently is expected to add $15.7 trillion to the global GDP by 2030. All of this means investors would be wise to take a closer look at some of the leading tech companies in this space, namely Alphabet (GOOG 1.24%) (GOOGL 1.31%), NVIDIA Corporation (NVDA 3.09%), and Amazon (AMZN 0.61%).

Image of a brain on a bright blue background.

Image source: Getty Images.

AI: As easy as A-B-C

Anders Bylund (Alphabet): The company formerly known as Google has data analytics and automation running through its proverbial veins. Moving on to artificial intelligence was always a natural next step, and Alphabet is leaning deeply into the AI space now.

In last month's second-quarter earnings call, CEO Sundar Pichai made that point perfectly clear:

We have been focused on our investments in AI. So that continues to be kind of a foundational investment we are making across the board, including getting a lot of our engineers trained on AI techniques etc. across the board. I think with AI, we are excited that we can give better experiences for users with less data over time. And those are the kind of directions we are pushing.

And I'm not even worried about some hungry start-up rising up to steal Alphabet's thunder, the way Google did in the online search and advertising markets long ago. This company has a penchant for identifying up-and-coming threats and promising challengers, then eliminating the existential threat by acquiring the smaller company. Alphabet entered the smartphone space in its infancy by buying out Andy Rubin's Android project. The $1.65 billion YouTube buyout looked preposterously expensive in 2006, but Alphabet has marshaled that asset into a profitable and fast-growing market leader.

The company has already completed at least four acquisitions in the AI field, led by the British DeepMind project. I'm sure there will be more in the coming years. In due time the memory of Google will fade away as Alphabet continues to establish itself as a leading provider of artificial intelligence tools instead.

And they're just getting started. You don't want to miss this massive investment opportunity for the very long haul.

Gaming the industry for growth

Rich Duprey (NVIDIA): Specialized chipmaker NVIDIA arguably covers the majority of the most dynamic, high-growth segments of the tech industry, its graphics processing units (GPUs) and processors powering not only high-performance gaming but also autonomous vehicles, automotive supercomputers, intelligent medical equipment, and other devices that require deep machine learning. 

But it's been a tough year or so for NVIDIA, which has suffered a slowdown in its gaming and data center businesses. And though the gaming industry is now beginning to adopt its next-generation ray tracing chip architecture for video games, the data center business is still undergoing a slow growth recovery, with revenues in its just-reported second-quarter earnings rising 3% sequentially.

Still, NVIDIA has essentially stabilized the business, and now it's ready for a comeback so it can resume its former meteoric rise. Net sales jumped 17% sequentially for the period, and though that's still down by a like amount year over year, gaming revenues surged 24% and autonomous vehicle revenues beat expectations with over $200 million in revenue, well ahead of Wall Street's forecast of $177 million. Admittedly it was due to a single deal in the quarter, but the self-driving car future is closer than it has been, and NVIDIA is strapped in for the ride.

Shares are down 43% over the past year, but analysts are looking for 30% growth in earnings this year and a 35% gain next year. Although it may still look pricey, this could be the inflection point this AI stock has been waiting for.

An under-the-radar AI bet

Chris Neiger (Amazon): It's easy to assume that the best AI stocks are the ones making the splashy AI headlines about new driverless car innovations or beating humans at games they've been playing for thousands of years. 

But then there are the companies, including Amazon, using AI in more subtle ways, to advance their own businesses. For example, Amazon's retail website uses machine learning, a type of AI, to forecast which products will be in the greatest demand, decide on product placement in search results, and display the right deals to the right customers.

But the company is also using AI to help make its cloud computing services, called Amazon Web Services (AWS), smarter and better as well. AWS offers AI features like speech translation, image recognition, and facial recognition to its users, allowing them to perform more complex tasks than ever before. Amazon's development of AI features in AWS matters because the company's cloud computing segment is its key moneymaker right now, bringing in more operating income than its retail business.

While Amazon doesn't look like the typical AI play, this company is knee-deep in the market, and it's one of the reasons Amazon will likely continue to dominate both the online retail and the cloud computing markets for years to come.