Artificial intelligence (AI) is no longer confined to a handful of headline-grabbing chipmakers. An analysis by BestBrokers of all 503 S&P 500 constituents revealed that 28 companies directly involved in building the hardware behind the AI boom now command a combined market capitalisation of $12.39 trillion.

From processors and memory to networking, manufacturing equipment and photonics, the AI value chain is deeply embedded across America’s flagship stock index.

At the heart of this surge lies AI computing, led by NVIDIA, AMD and Intel, worth $6.17 trillion alone. These firms produce the accelerators and processors that deliver the raw computing power essential for training and running advanced AI models. But the rest of the supply chain is equally formidable. Custom silicon and networking specialists such as Broadcom and Marvell add $2.12 trillion, while memory and storage giants including Micron and Western Digital contribute $1.73 trillion.

Further upstream, companies supplying chip manufacturing equipment, Applied Materials, Lam Research, KLA and Qnity Electronics, represent $1.26 trillion in market value. Supporting components like analogue, power and RF chips from Qualcomm, Texas Instruments and others account for $673.5 billion, while photonics and semiconductor testing firms add another $263.5 billion. Finally, design software providers Cadence and Synopsys round out the chain with $186.6 billion.

The findings underscore that the AI hardware boom is far broader than the marquee names dominating headlines. It spans every layer of infrastructure needed to transform AI designs into working systems, from the chips themselves to the tools, connectivity and testing that make them viable. In total, nearly $12.4 trillion of S&P 500 value is now directly tied to artificial intelligence, cementing AI as one of the most powerful forces reshaping corporate America’s future.

Data Analyst at BestBrokers, Alan Goldberg, said: “AI may be associated with chatbots and giant language models, but behind the software boom sits a vast hardware industry worth trillions of dollars. The AI boom has fundamentally changed the role of semiconductor and hardware companies, turning what was once a relatively specialised part of the tech supply chain into one of the most strategically important parts of the global economy. The 28 companies we identified have grown to over 18 per cent of the S&P 500 index, showing just how much value investors now attach to the infrastructure behind AI – not just the companies building the models themselves.

“The shift is also visible in the wider industry: AI demand is pushing semiconductor equipment investment sharply higher, while shortages in advanced memory, packaging and manufacturing capacity are giving suppliers greater pricing power. The weight and influence of these 28 companies on the U.S. stock market shows that AI is turning the semiconductor supply chain from a supporting cast into one of the main drivers of the technology economy.”