By TradingView
Publication Date: 2026-10-06 17:34:00
The U.S. stock market is becoming increasingly dependent on three mega-cap technology companies — Nvidia Corp. NVDA, Apple Inc. AAPL and Microsoft Corp.
MSFT.
The trio now accounts for more than 21% of the S&P 500, according to Creative Planning data cited by Yahoo Finance, marking the highest concentration in just three stocks in the benchmark’s history. By comparison, IBM IBM, AT&T Inc
T and ExxonMobil Holdings Corp
XOM together represented 13.4% of the S&P 500 at their peak in the mid-1980s.
That concentration matters for ETF investors because the largest S&P 500 funds are market-cap weighted, meaning the biggest companies receive the largest allocations.
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SPY, VOO Investors Have Significant Mega-Cap Exposure
The SPDR S&P 500 ETF Trust (NYSE:SPY) has Nvidia at 8.63%, Apple at 7.25% and Microsoft at 5.82%. Together, the three accounted for roughly 21.7% of SPY.
The Vanguard S&P 500 ETF (NYSE:VOO) showed a similar concentration, with Nvidia at 8.08%, Apple at 7.03% and Microsoft at 5.69%. That puts the combined exposure at about 20.8%.
This means investors buying broad-market ETFs are getting substantial exposure to the performance of just three companies, even though the funds hold hundreds of stocks.
QQQ Takes the Concentration A Step Further
The concentration is even more pronounced in the Invesco QQQ Trust QQQ, which tracks the Nasdaq-100.
Nvidia represents 8.53% of QQQ, Apple 7.2% and Microsoft 5.78%. Combined, the three accounted for…

