S&P 500

As of 2025-11-20, AI-related stocks constituted almost half of the market capitalization of the S&P 500.

In 2025, FactSet reported that four out of five S&P 500 companies that had reported earnings during that reporting season beat analysts' forecasts.

In 2025, FactSet indicated that with roughly two-thirds of S&P 500 companies having reported earnings, aggregate earnings for the S&P 500 were on track to grow by nearly 11% year-over-year.

Major regional stock market indices commonly used as benchmarks include Germany's DAX, France's CAC 40, Britain's FTSE 100, Japan's Nikkei 225, Hong Kong's Hang Seng, China's Shanghai Composite, South Korea's Kospi, Australia's S&P/ASX 200, Taiwan's Taiex, and the U.S. S&P 500 and Dow Jones Industrial Average.

The S&P 500 index is widely used as a benchmark that influences the performance and valuation of many U.S. 401(k) retirement accounts.

Rystad Energy reported that the green energy index was up 40% year-to-date in 2025, outperforming the S&P 500 total return by 25 percentage points in 2025.

The dot‑com bubble around 2000 burst and was followed by roughly a 50% decline in the S&P 500 index.

The S&P 500, the Dow Jones Industrial Average, and the Nasdaq Composite are major U.S. stock market indices widely used to measure overall U.S. equity market performance.

In market-capitalization-weighted indexes such as the S&P 500, the largest constituent companies can disproportionately influence the index's direction because larger market caps carry greater index weight.