Apple, Microsoft, Alphabet, Amazon, and Facebook account for ~18% of the S&P 500 index by market value
NEW YORK (AP) — Now that they've already taken over our lives, big tech companies are taking over the stock market. — The five biggest U.S. stocks — Apple, Microsoft … Tweets: @benbajarin and @whatthebit Tweets: Ben Bajarin / @benbajarin : This trend continues. https://twitter.com/... Stefan Constantine / @whatthebit : because everyone has an iPhone in their pocket, uses a Windows computer to get work done, performs at least a dozen Google searches a day, has an Amazon Prime account, and Facebook is where people talk to each other there's a reason for everything https://twitter.com/...
Context & Ripple Effects
The ~18% share the five biggest U.S. stocks hold of the S&P 500 is an early marker in a concentration arc this coverage has been tracking since late 2019, when Apple, Microsoft, Alphabet, and Facebook kept soaring despite trade-war and regulatory headwinds (their 2019 rally). What makes the number notable is how fast it moves afterward: within months the same five names are outperforming everything else in the index, and technology as a sector approaches its 1999 record share.
The trajectory only steepens from there — by mid-decade six companies including Nvidia and Meta hold 30% of the index, and by late 2025 eight tech stocks account for most of the gains off the April bottom. The February 2020 figure is the baseline against which all of that escalation gets measured.
First-order effects
- Index investors holding S&P 500 funds now have nearly a fifth of their exposure concentrated in five companies, so their portfolio performance tracks Apple, Microsoft, Alphabet, Amazon, and Facebook rather than the broad market.
Second-order effects
- Active fund managers benchmarked to the S&P 500 face mounting pressure to overweight these five names just to keep pace, reinforcing the same buying that drives the concentration higher.
Third-order effects
- If the pattern holds — and the coverage shows it accelerating through 2020, 2024, and 2025 — index composition itself becomes a systemic issue: fewer companies effectively set the market's direction, raising the stakes of any single stock's stumble and sharpening the regulatory scrutiny these firms already face.
The trend: U.S. equity markets are concentrating around a handful of tech giants at an accelerating pace, turning the S&P 500 into an increasingly top-heavy bet on Big Tech.