The artificial intelligence (AI) revolution began more than two years ago with the debut of ChatGPT in November 2022. Since then, the Nasdaq Composite is up more than 74%, while shares of Nvidia have advanced by a staggering 685%.

Yet, like all revolutions, the AI revolution will have stages. Clearly, Nvidia, the global leader in graphics processing units (GPUs), dominated the first wave of AI. But what will come next? Which stocks could come to rule the second stage of AI?

Perhaps the second phase of the AI revolution will see AI-based platforms take center stage. Here, three Motley Fool contributors reveal their stocks to watch: CrowdStrike Holdings (CRWD -0.45%), Alphabet (GOOG -0.54%), and Apple (AAPL 1.27%).

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AI-powered cybersecurity will grow in importance as data and operations become more centralized

Jake Lerch (CrowdStrike Holdings): My choice is CrowdStrike Holdings.

As AI systems continue to improve, one thing is becoming clear: AI-powered tools will be far more powerful than existing systems. Furthermore, those tools will be used for both ethical and unethical purposes.

In particular, cybercrime is already an enormous problem. According to the FBI, cybercrime costs hit $12.3 billion in the U.S. alone in 2023. As AI-powered models proliferate and grow more powerful, it's unfortunately true that criminals will attempt to use them.

Consequently, organizations will need to fight fire with fire. That's where CrowdStrike comes in. The company's AI-powered cybersecurity tools are dynamic -- built to learn on the fly and adapt to threats as they appear.

Just as the personal computer era needed firewalls and anti-virus software, the AI era will need dynamic, AI-powered cybersecurity to keep networks, endpoints, and data secure.

Moreover, the new AI era will mean organizations will become more vulnerable than ever as they work in real time to centralize, sort, and analyze their data. Simply put, that will make many organizations sitting ducks for cybercriminals who -- if they were to gain access -- could do enormous harm by either stealing data or shuttering operations, or both.

All this presents a huge market opportunity for CrowdStrike. As a result, over the last three years, the company's revenue more than doubled from $1.6 billion to $3.7 billion. Looking ahead, analyst estimates compiled by Yahoo! Finance predict CrowdStrike could generate $4.8 billion in revenue by the end of fiscal year 2026 (the 12 months ending on Jan. 31, 2026).

In other words, CrowdStrike is well positioned to scale along with the growth of AI. Therefore, investors looking to capture the next phase of AI growth should consider CrowdStrike stock.

This well-funded AI pioneer is setting itself up for a comeback

Will Healy (Alphabet): In the race for AI leadership, investors seem to have written off industry pioneer Alphabet.

Indeed, many analysts and investors questioned the market leadership of the Google parent after the functionality of OpenAI's GPT-4o became known to the public. Some appeared to doubt the future of Google Search amid AI advancements, and the release of the generative AI platform Google Gemini did not necessarily ease those concerns.

Still, DeepSeek's breakthrough could finally serve as the opportunity Alphabet needs to build a competitive advantage, setting it up to prosper in this next stage of AI development. Lower-cost AI should increase usage of the company's AI services and products, which should bode well for the company as it seeks to succeed in this burgeoning industry.

To that end, Alphabet is now betting its vast resources on a recovery. The company pledged to spend $75 billion in capital expenditures (capex) in 2025, most of which it will likely devote to AI-related spending. While some may perceive that as a sign of desperation, competitors such as Amazon and Meta Platforms also have spent comparable sums on capex.

Moreover, Alphabet can likely afford this. In addition to its $96 billion in liquidity, the company generated nearly $73 billion in free cash flow in 2024, which does not include capex. Also, the nearly $53 billion it spent on capex in 2024 indicates Alphabet can still generate massive free cash flows even with that added investment.

Alphabet stock has risen by almost 25% over the last year. So, while it has not performed as well as some peers, the stock remains in growth mode.

Finally, with a P/E ratio of 23, it is the lowest-cost stock in the "Magnificent Seven." This means it could offer growth stock returns at a reasonable price as it ups its competitive game in this new AI realm.

Apple's 2.35 billion iOS devices make the stock a no-brainer for AI's next stage

Justin Pope (Apple): Artificial intelligence is steadily entering its next phase. While AI hyperscalers continue to spend billions of dollars on chips and other hardware, the focus may soon shift to AI platforms and applications that bring the technology to consumers and businesses. I think Apple will be a massive long-term winner here.

The company is famous for its sticky ecosystem, which includes the iPhone, wearable accessories, tablets, and computers. Thanks to software that seamlessly ties everything together, the user experience is buttery smooth. As of earlier this year, Apple had approximately 2.35 billion active iOS devices worldwide. Its massive footprint gives Apple an inside track to capture market share in consumer-facing AI.

You've already seen the earliest iteration of Apple Intelligence, a package of generative AI features Apple introduced through software updates in its newest devices. Thus far, Apple Intelligence reportedly failed to make a great first impression with iOS users. However, it's incredibly early. A full rollout will take several years as iOS users upgrade to AI-capable devices, allowing Apple to experiment and improve Apple Intelligence.

The stock trades at a price-to-earnings ratio over 31, which some may argue is expensive for a company trying to reignite growth. However, assuming Apple succeeds in AI, the stock should be fine over the long term. Analysts estimate Apple will grow earnings by an average of almost 14% annually over the next three to five years.

Unless a competitor emerges and eats into Apple's vast user base, it seems appropriate to give the company the benefit of the doubt. Apple remains a world-class company that generated nearly $100 billion in free cash flow over the past four quarters alone. Until proven otherwise, Apple is on top of the consumer mountain, making it arguably the most obvious consumer-facing AI stock you can comfortably buy and hold for the next five to 10 years.