A close-up view of a computer circuit board featuring a central processing unit (CPU) surrounded by various electronic components and intricate wiring. Sach336699 / Shutterstock.com

The artificial intelligence (AI) boom relies on more than just chips and software — it’s built on robust physical infrastructure that handles massive data loads, power demands, and connectivity. As tech giants like Nvidia (NASDAQ:NVDA) and Microsoft (NASDAQ:MSFT) expand data centers to fuel AI growth, a quieter group of companies provides essential components.

Amphenol (NYSE:APH), Vertiv (NYSE:VRT), and Quanta Services (NYSE:PWR) supply interconnects, cooling systems, and power infrastructure, respectively, often overlooked but critical for scaling AI operations. With data center spending projected to surge through 2028, stocks in this niche offer strong growth potential amid the AI rush.

Investors eyeing long-term plays should consider these  three under-the-radar suppliers driving the revolution from behind the scenes.

Amphenol specializes in electrical, electronic, and fiber optic connectors used in everything from data centers to telecommunications. In the AI space, its high-speed interconnects are vital for linking servers and handling the data throughput required for training large language models. The company holds a commanding 33% market share in AI and data center interconnects, positioning it as a key player in infrastructure buildouts.

Recent quarters show this strength: in Q1 2025, Amphenol reported record results driven by AI-related demand, with sales in its communications solutions segment jumping due to design wins in next-gen hardware. Analysts project revenue to reach $26.9 billion by 2028, implying annual growth of about 12.7%, fueled by expansions in cooling and interconnect technologies tailored for AI factories.

The stock has doubled year-to-date, reflecting investor recognition of its role in tech trends, yet it trades at a reasonable forward P/E of around 36 given the multiyear tailwinds. For those betting on sustained AI infrastructure spending, Amphenol’s diverse portfolio and acquisition strategy make it a solid buy, as it benefits from both hyperscaler expansions and edge computing growth without direct exposure to chip volatility.

Vertiv delivers power, cooling, and IT infrastructure solutions, making it indispensable for data centers grappling with AI’s energy-intensive workloads. Its products, including liquid cooling systems and high-density racks, address the thermal challenges of GPU clusters, enabling efficient operation in AI environments.

In 2025, Vertiv has accelerated deployments with OCP-compliant power and cooling ecosystems, unveiled at industry summits, to handle gigawatt-scale AI demands. The company raised its full-year outlook multiple times this year, citing surging AI data center orders, with third-quarter sales and backlog hitting records, helping its stock to rise 71% this year.

Vertiv’s push into 800 VDC power architectures, set for a 2026 rollout, aligns with Nvidia’s platforms, further cementing its first-mover status in next-gen AI infrastructure. Financially, it’s a standout: analysts see it as a “no-brainer AI gold rush buy” with robust upside from hyperscaler commitments exceeding $300 billion in capex.

Trading at a premium valuation, the stock’s momentum — up over 1,200% over the past three years, comparable to Nvidia  — stems from its direct tie to the power crisis AI creates, where cooling efficiency can make or break data center viability. Investors should view Vertiv as a high-growth pick for the ongoing infrastructure wave, especially as global AI adoption ramps up.

Quanta Services is a leading contractor in electric power, pipeline, and renewable infrastructure, now pivotal in constructing the grids and facilities needed for AI data centers. Its expertise in transmission lines, substations, and power generation directly supports the massive electricity surge from AI operations, with projects tying into utility upgrades for hyperscalers.

In its just-reported third quarter results, Quanta reported strong sales and profits, as it expanded its platform to include integrated power solutions for large-load customers like data centers. The company has built over 80,000 megawatts of generation capacity historically, and recent contracts reflect AI-driven demand, boosting revenue to $7.6 billion, beating estimates.

Analysts highlight its bull case in the AI infrastructure build-out, with multiyear backlogs tied to grid modernization ahead of data center activations. Quanta’s stock has surged on this boom, yet its valuation remains attractive at around 37 times forward earnings, offering exposure to the “power crisis” AI exacerbates.

As North America’s grid strains under projected 50% capex growth through 2029, Quanta’s role in solving connectivity bottlenecks positions it for sustained gains, making it a must-buy for infrastructure-focused portfolios.