Summer 2026 Snapshot Of The S&P 500's Market Cap

The market capitalization of the S&P 500 (Index: SPX) rebounded strongly in the second quarter of 2026 after having shrunk by 1.5% in the first.

Since that Spring 2026 snapshot, the index's 503 stocks added $8.74 trillion to its total valuation, rising just shy of 15% over its market capitalization of three months earlier to reach a record high market cap of a shade over $67.185 trillion.

The index' top ten stocks contributed a little over a third of the index' total increase in value. Altogether, the combined market cap of these ten stocks account for 36.5% of the total value of the S&P 500, which believe it or not, represents a small decline from the 36.9% share they held at the end of March 2026.

The following chart shows the relative shares of the top 10 stocks in the S&P 500 at the end of the second quarter of 2026.

There has also been a change in the membership of the S&P 500's Top 10 stocks. Micron Technology (Nasdaq: MU has displaced Berkshire Hathaway (NYSE: BRK-B) from the tenth spot. Here are the approximate market capitalizations of each of the S&P 500's top ten component firms at the end of trading on 30 June 2026:

• Nvidia (Nasdaq: NVDA) $4,743,261,533,736 (7.06%)

• Apple (Nasdaq: AAPL $4,185,625,970,988 (6.23%)

• Microsoft (Nasdaq: MSFT) $2,774,740,812,228 (4.13%)

• Amazon (Nasdaq: AMZN) $2,539,593,285,768 (3.78%)

• Alphabet (A) (Nasdaq: GOOGL) $2,217,105,249,480 (3.30%)

• Alphabet (C) (Nasdaq: GOOG) $2,055,861,231,336 (3.06%)

• Broadcom (AVGO) (Nasdaq: AVGO) $1,760,247,198,072 (2.62%)

• Tesla (Nasdaq: TSLA) $1,551,973,674,636 (2.31%)

• Meta Platforms (A) (Nasdaq: META) $1,417,603,659,516 (2.11%)

• Micron Technology (Nasdaq: MU) $1,249,641,140,616 (1.86%)

Aside from Micron Technology's incredible ~750% year-long ascent to become one of index' Top 10 component stocks, there was some low level jockeying in the ranks of these most highly valued U.S. stocks. Meta Platforms dropped two positions from sixth to eighth as the company's missteps with its investments in AI technology proved costlier than anticipated, while both Broadcom and Tesla moved up one slot into the gaps left behind.

The S&P 500 now has 12 stocks for 11 companies whose market capitalizations exceed the trillion dollar level. Although no longer part of the index' top ten stocks, Berkshire Hathaway retained its trillion dollar valuation, while shares of Eli Lilly (LLY) (NYSE: LLY) rose to tie it for 11th place.

References

Standard and Poor. S&P 500 Factsheet. [PDF Document]. 30 June 2026. Accessed 1 July 2026.

SlickCharts. S&P 500 Component Weights. 30 June 2026. Accessed 1 July 2026.