Spring 2025 Snapshot of the S&P 500's Market Cap

The market capitalization of the S&P 500 (Index: SPX) shrank during the first quarter of 2025. Standard and Poor reports the index ended 2025-Q1 with a market cap of $49.41 trillion, a net decrease of $2.45 trillion (or 4.7%) from the $51.86 trillion recorded at the end of 2024-Q4.

Much of that decline was concentrated in the top 10 stocks that make up the market cap-weighted index, which collectively lost $2.78 trillion of their market capitalizations. The bottom 493 stocks that make up the index registered a net gain of $325 billion, which offset a portion of the losses registered by the index’ ten biggest component stocks.

In percentage terms, the S&P 500′s top 10 stocks went from accounting for 37.3% of the total valuation of the index to 33.6%. Their combined market capitalization is almost $16.58 trillion.

The following chart shows the relative shares of the top 10 stocks in the S&P 500 at the end of the first quarter of 2025.

Here are the approximate market capitalizations of each of the S&P 500′s top ten component firms at the end trading on 31 March 2025:

• Apple (NASDAQ: AAPL) $3,463,493,610,544 (7.01%)
• Microsoft (NASDAQ: MSFT) $2,900,243,579,728 (5.87%)
• Nvidia (NASDAQ: NVDA) $2,756,960,677,152 (5.58%)
• Amazon (NASDAQ: AMZN) $1,862,677,733,488 (3.77%)
• Meta Platforms (A) (NASDAQ: META) $1,309,309,282,160 (2.65%)
• Berkshire Hathaway (B) (NYSE: BRK.B) $1,012,861,897,520 (2.05%)
• Alphabet (A) (NASDAQ: GOOGL) $938,750,051,360 (1.90%)
• Broadcom (NASDAQ: AVGO) $815,230,307,760 (1.65%)
• Alphabet (C) (NASDAQ: GOOG) $765,822,410,320 (1.55%)
• Tesla (NASDAQ: TSLA) $751,000,041,088 (1.52%)

All but one of these stocks saw their market caps decline during 2025-Q1. Apple (NASDAQ: AAPL) held onto its position as the most valuable company in the world as measured by its market cap, even though it dropped by 10%.

But there’s a new Number 2 in this ranking. Or rather, an old Number 2, because Microsoft reclaimed the title of being the second-largest company in the S&P 500 despite its market cap falling by 10.7%. Meanwhile, former second-largest S&P 500 component Nvidia dropped to become the third-largest company in the index after its market cap dropped over 22% in value.

Amazon and Meta Platforms retained their respective fourth- and fifth-largest rankings within the index, despite market cap declines of 13% and 4% respectively.

Sixth place is now held by Berkshire Hathaway, which is the only one of the Top 10 components of the S&P 500 at the end of 2024 that saw its market cap increase during 2025-Q1. The company displaced Tesla, which saw the biggest percentage drop in its market cap among the top 10 index components, falling by 35% into tenth place.

The remaining three stocks, Alphabet (Class A shares), Broadcom, and Alphabet (Class C shares) clung to their seventh, eighth, and ninth place rankings, even though the Class A shares of Alphabet lost nearly 17% of their market cap, Broadcom lost 26%, and Class C shares of Alphabet lost over 19%.

All these losses took place before President Trump imposed global tariffs, which sent most stock prices plunging after 2 April 2025. Nearly all of the losses that occurred during 2025-Q1 took place after 21 February 2025, when the Chinese company behind the DeepSeek artificial intelligence system announced they would make its code open source the following week. That action effectively popped the AI bubble that had been inflating the value of the S&P 500 and many of its biggest component stocks through the end of the quarter.

The arrival of the global tariff war in April 2025 has since expanded the declines in the S&P 500′s market capitalization beyond those stocks whose valuations had inflated with the AI bubble of the preceding two years. We’ll see that impact in three months when we take our Summer 2025 snapshot of the S&P 500′s market capitalization.

References

Standard and Poor. S&P Market Attributes. [Excel Spreadsheet]. 31 March 2025. Accessed 1 April 2025.