Nvidia, Apple and Microsoft Hold 20.28% of S&P 500 Index

Nvidia, Apple and Microsoft had a combined weight of 20.28% in the S&P 500 in an Oct. 10, 2026 snapshot, while the benchmark’s 10 largest listed positions represented 39.03%.

Nvidia held the largest allocation at 7.78%, followed by Apple at 6.91% and Microsoft at 5.59%. Amazon ranked fourth at 3.98%.

The weights were calculated against total S&P 500 market capitalization of $71.12 trillion. The index uses float-adjusted market capitalization, giving companies with larger float-adjusted market values greater weight.

Rank Company Index weight

1 Nvidia 7.78%

2 Apple 6.91%

3 Microsoft 5.59%

4 Amazon 3.98%

5 Alphabet Class A 3.11%

6 Alphabet Class C 2.90%

7 Meta Platforms 2.57%

8 Broadcom 2.43%

9 Tesla 2.13%

10 Micron Technology 1.63%

Alphabet appeared twice because its Class A and Class C shares are two listed share classes of one company, not two separate companies.

The S&P 500 had 503 constituents as of Aug. 31, despite its name. The figures show that a small group of large companies represented a substantial share of the index.

Information Technology was the largest sector at 37.9% of the index as of Aug. 31. That sector figure predates the Oct. 10 ranking and is not directly comparable with the 39.03% total for the 10 largest listed positions, which includes companies outside the sector.