IS THE U.S. STOCK MARKET TOO DEPENDENT ON AI?

Artificial intelligence has become one of the biggest forces influencing the U.S. stock market.Companies connected with AI chips, cloud computing, data centres and software have attracted significant investor interest.Their rising share prices have helped major indices such as the S&P 500 and Nasdaq move higher.But this creates an important question:
Is the wider U.S. market genuinely strong or is its performance being driven mainly by a small group of AI-related companies?

HOW AI IS SUPPORTING THE MARKET

AI is not limited to chatbots or software applications. It requires an entire physical and digital ecosystem.

• The AI investment chain includes:
• Semiconductor companies producing advanced chips
• Cloud companies providing computing capacity
• Data centres storing and processing information
• Networking companies connecting servers
• Utilities supplying electricity
• Cooling companies controlling data-centre temperatures
• Cybersecurity companies protecting data and systems
• Software companies developing AI-based products

Companies such as NVIDIA, Microsoft, Amazon, Alphabet, Meta and Broadcom are directly or indirectly connected to this growth.AI spending can therefore benefit several industries. However, because many AI leaders carry significant weight in the S&P 500 and Nasdaq, their price movements can strongly influence the wider market.

WHY MARKET CONCENTRATION MATTERS

The S&P 500 contains 500 leading U.S. companies, but not every company has the same weight.Larger companies receive a larger weight in the index.By mid-2025, the 10 largest companies represented almost 40% of the S&P 500, the highest concentration since the mid-1960s.This means a small number of companies can have a very large effect on the index.For example:
If a few major technology companies rise sharply, the S&P 500 may increase even when many other companies are not performing well.Therefore, a rising index does not always mean that the entire market is equally strong.

WHY THE AI BOOM MAY CONTINUE

AI could continue to support the U.S. economy because its use is expanding across different industries.Businesses are using AI to:

• Automate routine work
• Improve customer service
• Develop medicines
• Detect financial fraud
• Analyse large amounts of data
• Improve manufacturing
• Create software and digital content
• Reduce operating costs

By July 2026, companies had announced over $1.5 trillion in data-centre investments, suggesting that major spending on chips, servers, power and cooling may still lie ahead, potentially supporting long-term business growth and earnings.

WHAT COULD GO WRONG?

AI has strong potential, but market expectations are already high.

• HIGH VALUATIONS: AI stocks may fall if their growth is below expectations.
• HEAVY SPENDING: Companies must earn sufficient profits to justify their large AI investments.
• SUPPLY CONSTRAINTS: Shortages of chips and electricity could increase costs and delay projects.
• COMPETITION: New and cheaper technologies may reduce the profits of current market leaders.
• REGULATION: Rules relating to data, competition and copyright may increase business costs.

If AI growth slows, AI-dependent market indices could face greater volatility.

WHAT SHOULD INVESTORS LEARN?

The U.S. stock market has become highly influenced by AI and a relatively small group of large companies.However, the U.S. market is not only about AI.It also includes established companies across:

• Healthcare
• Banking and financial services
• Consumer products
• Energy and utilities
• Industrials and manufacturing
• Defence and aerospace
• Real estate
• Communication services

A balanced approach may include exposure to:

• Large technology companies
• Other U.S. market sectors
• Broad-market or equal-weight ETFs
• International markets
• Fixed-income investments