Analysis
Headline index levels can look very different from what the typical stock has done. The S&P 500 gives bigger companies more influence, so a handful of very large chipmakers and AI-related firms can lift the index even when many other members decline. Reuters' figures show how wide that gap has become this year.
What Reuters found
A Reuters analysis of data from LSEG, the financial data provider, found that the S&P 500 is up about 14% in 2026 and at record highs, while more than 4 in 10 of its stocks are lower for the year [1]. More than 200 members have fallen, and a quarter of the index is down 11% or more [1].
The median S&P 500 stock, the one in the middle when members are ranked by performance, has gained barely 4% in 2026, according to the analysis [1]. The article was published early on October 12 and does not state the trading date its figures run through; the last U.S. close before publication was October 9 [1]. The analysis covers current index members and leaves out 18 companies removed from the index during 2026, some of which moved to smaller-company indexes after their shares fell [1].
Why the index and the typical stock differ
The S&P 500 is weighted by market capitalization, meaning each company's influence on the index is proportional to the total value of its shares. A company worth several trillion dollars moves the index far more than one worth a few billion. An equal-weighted version of the same 500 companies instead gives each stock the same share, so a small company's move counts as much as a giant's.
The median stock is a related but separate yardstick: it ignores size entirely and asks how the middle company fared. A large gap between the cap-weighted index and the median stock, as in the Reuters figures, indicates that gains are concentrated in the biggest names [1].
Where the gains came from
Of the index's 11 sectors, eight are up this year, led by energy at about 42% and technology at about 32% [1]. Because technology is so large within the index, it accounts for more than 10 percentage points of the S&P 500's 14% gain, while energy's contribution is under 1% [1].
Reuters reported that Nvidia, which it called the world's most valuable company, has contributed almost 2 percentage points to the index's gain this year, followed by more than 1 point each from Apple, Micron Technology and Advanced Micro Devices (AMD) [1]. The memory-chip makers Sandisk and Micron have more than tripled in price [1]. Tesla, down about 15% this year, has subtracted about 0.3 percentage point [1].
Reuters tied the strength of AI-related stocks to what it called explosive earnings growth at those companies, while profit growth in other sectors has been tepid [1].
Other signs of narrow strength and analysts' views
Reuters reported that fewer than half of current S&P 500 companies trade above their 200-day moving averages, a common gauge of a stock's longer-term trend; a week earlier the share was about 40%, the lowest since May 2025 [1]. It also said the Federal Reserve's September rate increase and expectations of further increases have raised concerns about the economy and dented demand for industrial, consumer-goods and real estate companies [1].
Ross Mayfield, an investment strategy analyst at Baird, told Reuters that anything outside the AI trade or companies that benefit from higher energy prices faces headwinds from higher oil and yields [1]. Tim Ghriskey, a senior portfolio strategist at Ingalls & Snyder, said AI is so strong a story that it attracts managers and assets, and that he expects some rotation away at some point before AI comes back [1]. Strategists at Morgan Stanley wrote in a recent report that they favor large-cap quality companies and would add riskier stocks over the next month if the index comes down [1]. These are the analysts' views, not established outcomes.
What remains uncertain
Reuters does not state the exact trading date its figures run through; the article was published before U.S. markets opened on October 12, so they likely reflect the October 9 close. The analysis covers only current index members. Analysts' comments are opinion, and the figures change with each trading day.