2026 is rapidly becoming one of the strongest years in history for companies linked to artificial intelligence. While the year is far from over, the market has already delivered remarkable results. The S&P 500 has gained approximately 8.4% since the beginning of the year, which is already a solid performance for the benchmark U.S. stock index. However, against this backdrop, several individual companies have achieved gains that would have seemed almost impossible just a few years ago.

Five companies within the S&P 500 have increased their share prices by more than 200%, with some posting gains exceeding 500%. What makes this rally particularly interesting is that the biggest winners are not AI giants such as NVIDIA, Microsoft, or Alphabet. Instead, investors have focused on infrastructure providers – companies supplying the hardware and systems that make modern AI possible.

As artificial intelligence expands, demand for memory chips, servers, data storage systems, and computing power continues to surge. As a result, infrastructure companies have become some of the market’s biggest beneficiaries.

SanDisk (SNDK) – The Year’s Top Performer

The standout winner among S&P 500 companies is SanDisk. Since the start of 2026, its shares have soared an astonishing 591.7%.

The rally is driven not only by strong demand for storage devices but also by growing expectations for data center expansion. Investors are betting on rapidly increasing memory requirements for training and operating large AI models.

Analysts expect SanDisk’s earnings per share (EPS) to increase by more than 2,091% this year, an extraordinary figure rarely seen among major public companies.

Micron Technology (MU) – Memory for the AI Era

Micron Technology remains one of the biggest beneficiaries of the AI boom. Its shares have climbed 232.6% since the beginning of the year.

The company has benefited from strong demand for high-performance memory used in AI training and modern data centers. Every new generation of AI models requires larger amounts of memory and faster data processing capabilities.

Analysts forecast a 615% increase in Micron’s earnings during 2026, followed by an additional 77% growth in 2027.

Dell Technologies (DELL) – An Unexpected AI Star

Many investors still associate Dell Technologies primarily with personal computers. However, the company now plays a critical role in AI infrastructure.

Its shares have gained 218.4% this year.

Dell supplies servers to major data centers used by leading technology companies. These servers form an essential part of the infrastructure required to train and deploy advanced AI systems.

Seagate Technology (STX) – A Bet on Data Storage

The growth of artificial intelligence is generating unprecedented volumes of data. AI systems require massive storage capacity, creating strong demand for products from Seagate Technology.

The company’s stock has risen 218.4% since the start of the year. Cloud services, enterprise databases, machine learning systems, and digital platforms continue to generate enormous amounts of information, driving demand for storage solutions.

Western Digital (WDC) – Completing the Top Five

Western Digital rounds out the list with a gain of 205.9% since the beginning of 2026.

Like its peers, the company benefits from growing demand for storage devices and data infrastructure. The continued expansion of data centers worldwide supports strong demand for its products.

Why Investors Are Shifting Toward Infrastructure

This rally differs significantly from earlier stages of the AI boom. During 2023-2025, investors focused primarily on AI developers and GPU manufacturers. In 2026, attention shifted toward the infrastructure layer that powers the entire ecosystem.

More investors are realizing that regardless of which AI company ultimately dominates the market, all AI systems require massive investments in storage, computing, networking, and data management infrastructure.

What’s Next?

Despite the impressive gains, many analysts believe the AI investment cycle is still in its early stages. Major technology companies continue to invest tens and even hundreds of billions of dollars into building new data centers, expanding cloud platforms, and developing increasingly powerful AI models.

At the same time, investors should remember that rapid growth often comes with significant volatility. Stocks capable of rising several hundred percent within months can also experience sharp corrections.

Nevertheless, one trend is becoming increasingly clear: artificial intelligence is no longer just a software story. It is now a vast ecosystem that includes memory manufacturers, server providers, storage companies, and computing infrastructure suppliers. These companies are increasingly emerging as some of the biggest winners of the ongoing technological revolution.