Microsoft, Meta and Amazon Earnings Could Put the S&P 500 Under Pressure

This week’s earnings reports from Microsoft (NASDAQ:MSFT), Meta Platforms (NASDAQ:META) and Amazon (NASDAQ:AMZN) could have an unusually large impact on the entire US stock market.

The main issue is not whether these companies will report revenue growth. Investors will be watching how much they are spending on artificial intelligence and whether those investments are beginning to produce measurable returns.

Because the S&P 500 has become increasingly concentrated in a small number of technology companies, disappointing reactions to these reports could pull the broader index lower.

The ten largest stocks now represent approximately 38% of the S&P 500. That is significantly higher than the roughly 27% concentration reached during the dot-com bubble.

As a result, investing in the S&P 500 has increasingly become a bet on large technology companies and the continued growth of artificial intelligence.

When Microsoft, Amazon, Meta, Nvidia or Alphabet move sharply, the impact is felt across the entire index.

This concentration has helped drive the market higher, but it also creates additional risk. Weakness in only a few major stocks could outweigh gains across hundreds of smaller S&P 500 companies.

Alphabet’s Earnings Showed the Risk

Investor concerns increased after Alphabet (NASDAQ:GOOG) reported higher-than-expected capital expenditures.

The company spent $44.9 billion during the second quarter, slightly above Wall Street’s forecast of $44.7 billion. Alphabet also raised its full-year capital expenditure guidance to between $195 billion and $205 billion, compared with its previous outlook of $180 billion to $190 billion.

Management additionally warned that spending could increase significantly again in 2027.

Although Alphabet continues to generate strong revenue and cash flow, investors reacted negatively to the size and expected duration of its AI investments. The stock fell approximately 9% over five trading sessions and moved below its 200-day moving average.

That reaction suggests the market may no longer automatically reward companies for increasing AI spending.

Microsoft, Meta and Amazon Face the Same Question

Microsoft, Meta and Amazon are also expected to report substantial increases in capital expenditures.

All three companies are investing heavily in data centres, AI chips, cloud infrastructure and new artificial intelligence products. Their guidance could indicate that this spending will remain elevated for several years.

Investors will therefore focus on whether revenue and profit growth are keeping pace with these investments.

Strong spending may be viewed positively when it produces faster cloud growth, higher advertising revenue or better operating margins. However, if costs rise faster than earnings, the market may question whether these companies are overinvesting.

Cheaper Chinese AI Models Are Increasing Concerns

New artificial intelligence models from China are also challenging assumptions about how much AI infrastructure companies need.

Moonshot AI’s lower-cost Kimi K3 model has been compared with the DeepSeek release that disrupted technology stocks in early 2025.

These models raise the possibility that advanced AI systems could be developed and operated with less computing power than US technology companies currently expect.

If AI becomes cheaper and more efficient, investors may question whether hundreds of billions of dollars in spending on chips and data centres will generate sufficient returns.

Barclays strategists have warned that investor enthusiasm for AI capital expenditure is beginning to weaken.

What Could Happen to the S&P 500?

Microsoft, Meta and Amazon could report strong results and still face selling pressure if their spending forecasts exceed market expectations.

Because these companies represent such a large share of the S&P 500, a simultaneous decline could pull the broader index sharply lower.

The reaction may depend on three factors:

• How quickly AI investments are generating additional revenue
• Whether capital spending is expected to stabilise
• Whether profit margins can remain strong despite higher infrastructure costs

If investors remain uncomfortable with the level of spending, money could move away from large technology companies and into less expensive sectors such as healthcare, financials or industrials.

What This Means for Investors

The upcoming reports will test whether the market still believes that aggressive AI investment will produce sufficient long-term returns.

Strong earnings alone may not be enough. Investors increasingly want proof that AI spending is improving revenue growth, productivity and profitability.

A positive reaction could support the S&P 500 and extend the technology-led rally. A negative reaction could expose the risks created by the index’s record concentration and trigger a broader rotation into other sectors.