Key takeaways Three chipmakers could generate 40% of S&P earnings growth Semiconductor stocks weaken despite exceptional AI profit forecasts Broadcom CEO questions returns on corporate AI
Nvidia, Broadcom and Micron Technology are expected to account for nearly 40% of the S&P 500's third-quarter earnings growth, revealing how heavily the US stock market depends on a small group of semiconductor companies benefiting from artificial intelligence investment.
The estimate, based on Goldman Sachs data reported by Axios, comes as the S&P 500 trades near record highs despite renewed weakness in semiconductor shares and rising Treasury yields.
According to FactSet's October earnings outlook, S&P 500 profits are projected to increase approximately 29.6% year over year in the third quarter. Historical earnings surprises suggest the final growth rate could exceed 35%.
<iframe src=”https://widgets.coincodex.com/w/1345e2f8-ef0d-49bf-bdde-5af5b4cd9a6f?site=coinpaper&mode=light” width=”100%” height=”628” frameborder=”0” referrerpolicy=”no-referrer-when-downgrade” style=”border:0;background:transparent;border-radius:0px;”></iframe>Three AI Chipmakers Could Account for 40% of S&P 500 GrowthThe concentration is particularly striking because the S&P 500 includes roughly 500 companies spanning financial services, healthcare, energy, industrials and technology.
Yet Nvidia, Micron and Broadcom are projected to generate nearly two-fifths of the index's incremental earnings growth, reflecting their exposure to AI infrastructure spending.
Nvidia benefits from demand for AI accelerators, while Micron supplies high-bandwidth memory essential for advanced computing systems. Broadcom provides custom AI processors and networking technology used in large-scale data centers.
The earnings contribution refers to the increase in aggregate profits compared with a year earlier, not the three companies' share of total S&P 500 earnings.
The figures illustrate why AI companies have helped sustain the broader S&P 500 rally despite borrowing costs remaining historically elevated.
However, they also raise concerns about how much of the market's profitability depends on a small group of semiconductor suppliers.
AI Stocks Fall as Broadcom CEO Questions Investment ReturnsThe earnings outlook contrasts with recent semiconductor stock performance.
The Philadelphia Semiconductor Index declined for a fifth consecutive session on October 13, while Applied Materials dropped approximately 6.7% after announcing plans for a $5 billion advanced research facility in Silicon Valley.
The weakness suggests investors are becoming increasingly selective about AI infrastructure spending, particularly when major projects require substantial upfront investment.
Broadcom CEO Hock Tan added to the debate during a conference in Singapore, questioning whether many corporate AI customers are receiving meaningful returns from their investments.
His remarks are notable because Broadcom is itself a major supplier to AI infrastructure operators, making the company a direct beneficiary of the spending trend.
The latest reversal follows earlier Nasdaq strength, when strong semiconductor earnings helped offset pressure from Treasury yields above 5%.
Can the S&P 500 Sustain Its Rally Without AI Stocks?The broader market remains vulnerable to changes in semiconductor earnings expectations.
Reuters reported that more than 40% of S&P 500 stocks had declined in 2026 despite the index advancing approximately 14%, illustrating the divide between headline index performance and individual stocks.
Meanwhile, September US inflation reached 3.7%, increasing the risk of further Federal Reserve tightening and placing additional pressure on technology valuations.
Higher interest rates make distant corporate profits less valuable in present terms, meaning even companies reporting strong earnings may struggle to maintain elevated valuations.
That tension was visible during the recent AI stock divergence, when technology strength masked weakness across other sectors.
