These 3 AI Stocks Could Soon Enter the S&P 500. Are They Worth Buying Before the Move?

The artificial intelligence (AI) boom is creating opportunities beyond tech giants. Astera Labs (NASDAQ: ALAB), Credo Technology Group (NASDAQ: CRDO), and Sanmina (NASDAQ: SANM) are three promising companies benefiting from rising AI spending. None of the three was added to the S&P 500 in September, and the next rebalance should take effect Dec. 21.

To be included in the S&P 500, a company requires a market capitalization of at least $22.7 billion and positive earnings. If AI spending continues to drive massive growth, these stocks could emerge as future S&P 500 candidates, potentially rewarding investors who get in early.

Astera Labs, the largest of the three by market value, comes first.

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1. Connectivity chips are driving Astera Labs' rapid growth

Astera Labs develops connectivity solutions that move data between chips, memory, and other components in AI systems. As these systems become more complex, the connections between them can become a bottleneck. Astera's products are addressing that challenge. The company is already expanding beyond its established connectivity products.

Its Scorpio fabric switches help connect large numbers of AI chips, while its optical connectivity and custom solutions offer greater opportunities as AI data centers evolve.

With Astera, investors demand solid growth, as evidenced by the stock's forward price-to-earnings (P/E) ratio of almost 45 times. But the results are already showing up in earnings.

Astera has also attracted attention as a potential S&P 500 addition; in fact, its $45 billion market cap already clears S&P's $22.7 billion minimum. The main risk, however, is that its growth depends heavily on AI spending, while competition and changing connectivity standards could challenge its position.

Meanwhile, another company is tackling the broader challenge of moving data across advanced AI data centers.

2. Optical products could widen Credo's reach in AI data centers

Credo develops high-speed connectivity products spanning copper and optical solutions, helping customers move data reliably across AI infrastructure. Its portfolio includes active electrical cables, optical digital signal processors, and other networking products.

One of the most interesting developments is Credo's expansion into optical connectivity. Although copper is useful for short-distance connections, optical technology can become more attractive as data rates and transmission distances grow. This gives the company broad exposure to various networking hardware used in AI data centers.

Its combination of growth, profitability, and expanding product opportunities makes Credo a possible S&P 500 candidate. At $33 billion, its market value already tops S&P's $22.7 billion minimum. It was also identified among possible additions in September 2026.

That said, the company faces risks around customer concentration, competition, and reliance on AI spending. And with the stock trading at 28 times forward P/E, it could look reasonable to investors backing its AI-driven growth.

The next company offers a unique way to invest in the AI boom by manufacturing hardware that keeps data centers running.

3. Manufacturing hardware gives Sanmina a role in AI data centers

Sanmina provides manufacturing solutions for electronic and industrial systems. Its work spans areas like communications networks and cloud infrastructure. As data center operators expand their infrastructure, the demand for reliable manufacturing partners will only accelerate.

Building out data centers requires more than just chips; it involves networking equipment, power systems, and other hardware. And Sanmina's manufacturing capabilities allow it to participate in that broader supply chain.

To further strengthen its capabilities, it acquired ZT Systems' manufacturing business to expand its presence in cloud and AI infrastructure manufacturing.

Sanmina moved up from the S&P SmallCap 600 to the S&P MidCap 400 in June 2026, which provides a stronger path to potential S&P 500 inclusion. However, its $9.4 billion market value sits well below S&P's $22.7 billion minimum.

The risk is that the company earns lower margins than many chip designers, while customer concentration and slower data center spending could affect growth. But at a forward P/E ratio of just over 12, the stock could be a more value-oriented way to invest in the AI boom.

The question now is whether these three companies can sustain their growth and meet the requirements for inclusion in the S&P 500.

These AI stocks could be the S&P 500's next additions

Astera Labs, Credo Technology, and Sanmina are well-positioned to benefit from the AI spending boom, and continued growth could bring them closer to joining the S&P 500.

Investors willing to get in early may want to keep these three stocks on their radar. If these companies continue to expand, an S&P 500 inclusion announcement could be around the corner, potentially giving their shares a major boost.

Rick Orford has no position in any of the stocks mentioned. The Motley Fool recommends Astera Labs. The Motley Fool has a disclosure policy.