Benchmark equity indices at a glance
This reference lists the world’s most-watched stock market indices — the S&P 500, FTSE 100, DAX, Nikkei 225 and more — together with the exchange they trade on, the country they represent, the approximate number of constituent companies, and the weighting method that drives how they move.
How it works
A stock index aggregates the prices of its constituent shares into a single number. The weighting method determines each company’s influence. In a market-capitalisation weighted index, a company’s weight equals its market value relative to the whole basket, so giants dominate. In a price-weighted index, the weight depends only on share price, so a high-priced stock sways the index even if the company is modest in size:
cap-weighted: weight_i = (price_i × shares_i) / Σ(price × shares)
price-weighted: weight_i = price_i / Σ(price)Providers rebalance the basket on a schedule, adding and dropping companies to keep the index representative.
Notable indices and what they represent
S&P 500 (USA). Approximately 500 large US companies, cap-weighted by the S&P Dow Jones Indices committee. Because it is cap-weighted, the largest technology companies can represent a significant fraction of the total index. It is the most widely used benchmark for US equity performance.
FTSE 100 (UK). The 100 largest companies listed on the London Stock Exchange by market capitalisation, maintained by FTSE Russell. The index is internationally oriented — many FTSE 100 constituents earn most of their revenue outside the UK, which means it does not always track the UK domestic economy closely.
DAX (Germany). Originally 30 constituents, expanded to 40 in 2021, covering Germany’s largest listed companies on Deutsche Börse. Unlike most major indices, the DAX is a total return index by default, meaning dividends are reinvested in its calculation — making direct comparisons to price-return indices require care.
Nikkei 225 (Japan). Price-weighted rather than cap-weighted, covering 225 prominent Japanese companies on the Tokyo Stock Exchange. Because it is price-weighted, a single high-priced stock can move it substantially regardless of the company’s actual market size.
Hang Seng (Hong Kong). Covers major companies listed on the Stock Exchange of Hong Kong, with both local firms and China-linked companies in the basket. Serves as the primary benchmark for Hong Kong equities.
MSCI World. Not tied to a single exchange or country — covers large and mid-cap stocks across many developed market countries. Widely used as a global benchmark by institutional investors and is the basis for many international index funds.
Why weighting method matters when reading the news
When the financial press says “the Dow was up 1%,” that reflects a price-weighted movement. A single high-priced constituent like a stock trading in the hundreds of dollars per share influences it far more than a company with a lower share price, even if the lower-priced company is larger by market cap. The S&P 500 and FTSE 100 behave differently: their heaviest movers are the companies with the largest total market values.
For comparing the same economy over time, cap-weighted indices tend to be more representative. For comparing across indices from different countries, currency effects and index methodology both apply — a local currency index rising 5% may look different in your home currency.
Using the exchange and country columns
Not every exchange is in its country’s domestic capital. The Tokyo Stock Exchange handles the Nikkei 225; the KOSPI is the Korea Stock Exchange in Seoul. Some indices span multiple countries. Matching an index to its exchange country before interpreting it as an economic indicator avoids confusion when indices occasionally diverge from the domestic economy they are assumed to represent.