NVIDIA represents 8.08% of Vanguard S&P 500 ETF

Semiconductor manufacturer NVIDIA represented 8.08 percent of the Vanguard S&P 500 ETF (VOO) as of 31 August 2026. In a $500,000 portfolio, this corresponds to a single position of $40,400 in a single company – even though investors expect broad diversification across hundreds of stocks with an S&P 500 ETF.

This concentration is the result of automatic index mechanics: the S&P 500 weights companies by their market capitalisation, so the fund's weighting moves daily with price movements. NVIDIA's share of the VOO thus reflects its exceptional market growth. The stock rose 1,005.49 percent over the five years to 9 October 2026, while the VOO gained 90.68 percent over the same period. On 11 October 2026, NVIDIA reached a market capitalisation of $5.536 trillion.

Top 10 positions account for nearly 40 percent of fund assets

The concentration is not limited to NVIDIA. The ten largest positions in the VOO weighted 37.78 percent combined as of 31 August 2026. With $500,000 invested, this means $188,900 is in just ten stocks, while $311,100 is allocated to the remaining positions.

The ten largest positions include, alongside NVIDIA, Apple, Microsoft, Amazon, Alphabet (with two share classes), Broadcom, Meta Platforms, Micron Technology and Tesla. Earlier data from 28 February 2026 shows a similar pattern: at that time, the VOO held around 518 stocks, but the ten largest positions accounted for 36.35 percent of fund assets, with the top 25 accounting for approximately 50.2 percent. This represents a significant deviation from historical norms.

Technology sector dominates weighting

A source from September 2026 put the weight of the technology sector in the VOO at 36.6 percent. In 2026, the S&P 500 rose 14 percent and reached record highs, but this rally was heavily concentrated in AI-related semiconductor companies such as NVIDIA, SanDisk and Micron Technology. More than 40 percent of the stocks included in the index posted losses in 2026 despite the overall gains of the index.

Weighting shifts occur daily as stock prices change. The Vanguard prospectus lists 503 components in the S&P 500 Index as of 31 December 2025. The market capitalisation-weighted method means that a company's share in the fund automatically follows its size – without discretionary decisions.

Volatility and concentration risk

NVIDIA exhibits high sensitivity to market movements with a beta of 2.216. In the week to 9 October 2026, NVIDIA stock fell 2 percent while the VOO gained 1.14 percent. On 26 August, NVIDIA reported quarterly revenue of $96.22 billion – an increase of 105.85 percent compared to the prior year quarter.

The VOO prospectus warns of concentration risks. Sources point out that while investors assume their capital is spread across hundreds of companies, the fund holds a growing share in a small group of mega-cap technology and AI-driven titles. This could redefine the meaning of "diversified" for investors. Research from the CFA Institute warns that this technology concentration could weaken future returns for retirees.

The concentration pattern emerges from automatic index mechanics rather than active portfolio decisions. A source notes that the next price downturn in the VOO is likely to be determined by the valuation metrics of mega-cap technology stocks.