The market capitalization of the S&P 500 (Index: SPX) grew by 4.2% during the course of the second quarter of 2024. The index ended 2024-Q2 with a market cap of $47.83 trillion according to Standard and Poor.

The Top 10 stocks within the market cap-weighted index together accounted for 35.8% of its total valuation. That share is up from the 32.5% recorded at the end of 2024-Q1 and is also up from the 30.9% share that the S&P 500's Top 10 stocks held at the end of 2023.

The biggest market cap gain within the index belongs to artificial intelligence computer chip maker Nvidia (NASDAQ: NVDA), which rose from third to second-place during the preceding three months. That change however is somewhat misleading because for a brief moment about two weeks before the end of the quarter, NVDA became both the largest company within the S&P 500 index and the world. The company lost over $300 billion worth of its market valuation to drop back into second place behind Microsoft (NASDAQ: MSFT).

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 2024. Other than their ranking, there was no change in the membership of the ten most valuable companies within the index.

Here are the market capitalizations of each of the S&P 500's top ten component firms at the end of Friday, 28 June 2024:

• Microsoft (MSFT) $3,465,750,695,214 (7.25%)
• Nvidia (NVDA) $3,170,505,200,450 (6.63%)
• Apple (AAPL) $3,167,396,346,221 (6.62%)
• Amazon (AMZN) $1,846,420,269,779 (3.86%)
• Meta Platforms (A) (META) $1,152,810,976,881 (2.41%)
• Alphabet (A) (GOOGL) $1,116,269,982,551 (2.33%)
• Alphabet (C) (GOOG) $935,143,352,279 (1.96%)
• Berkshire Hathaway (B) (BRK-B) $768,365,279,990 (1.61%)
• Eli Lilly & Co. (LLY) $754,112,379,060 (1.58%)
• Broadcom (AVGO) $729,672,001,962 (1.53%)

The remaining 493 firms of the S&P 500 index account for 64.2% of its total market valuation. Their collective market cap declined over the quarter, falling from $30.96 trillion to $30.72 trillion. All the net increase in the market capitalization of the S&P 500 is effectively concentrated within its top ten components.

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