Global stock markets were worth about $164.5 trillion in September 2026. That figure says little about what an investor owns, or how exchanges, indexes and broad-market funds differ.
On an ordinary trading day, investors buy and sell shares through brokerage platforms, not by walking onto an exchange floor. A share gives its owner a stake in a company, but its price can fall as well as rise. That matters.
The Dow Jones Industrial Average was first published in 1896. Because it covers 30 companies, it may offer a less complete picture of the overall market than broader indexes.
Where shares trade
Most investors buy and sell stocks through online brokerage platforms. They rarely visit an exchange or call a stockbroker. Trades take place on exchanges such as the New York Stock Exchange in New York and the electronic Nasdaq, which lists many major technology companies. London, Tokyo, Toronto, Paris, Shanghai and Frankfurt also have major exchanges.
Most U.S. stock and ETF trades settle on a T+1 cycle: a trade made on Monday generally settles on Tuesday. The shift from T+2 took effect in May 2024 after a change to SEC rules.
In September 2026, global stock markets had a combined market capitalization of about $164.5 trillion and roughly 59,500 listed companies. Market capitalization is the value assigned to a company's outstanding shares at market prices. It is not the same as revenue, profit or cash available to shareholders. A September 30 market summary valued Nvidia at about $5.56 trillion, Apple at $4.93 trillion, Alphabet at $4.3 trillion and Microsoft at $3.85 trillion. Those figures are market valuations, not measures of revenue or cash.
Indexes tell different stories
News reports often use an index as shorthand for the market. The Dow Jones Industrial Average tracks 30 companies selected as representative of the U.S. economy. The S&P 500 follows 500 of the largest publicly traded U.S. companies and accounts for about 75% of the total value of the U.S. stock market. The Nasdaq-100 tracks the 100 largest nonfinancial companies listed on Nasdaq and has a heavier technology focus.
The Dow works differently from a market-cap-weighted index. It is price-weighted, so a company's influence depends on its share price, not its total market value. A special divisor helps keep the index comparable after stock splits and membership changes, as explained in this overview of Dow methodology. A committee can change the Dow's membership when corporate events or market conditions call for it. The committee does not make changes only at a fixed annual review.
These indexes are not interchangeable. A technology-heavy index can move differently from a broader group of large companies, and both leave out many smaller stocks. The S&P 500 is a common benchmark, but a fund that tracks it does not own the entire U.S. market. Market capitalization also helps explain why a smaller company may have more room to expand. That possibility is not a forecast, as this market-cap breakdown explains.
When a headline says stocks rose or fell, it often means the S&P 500 moved. That shorthand can hide differences in company size, sector exposure and performance. Janus Henderson's review of September 2026 said global equities declined overall, with notable pressure in Europe, China and Australia. It cited rising bond yields and oil prices among the factors.
What a total-market fund includes
The Vanguard Morningstar Total Stock Market ETF, known as VTI, holds 3,507 U.S. stocks, including companies beyond the largest 500. It includes large-, mid- and small-cap stocks, as well as growth and value companies. That is the core difference between a total-market fund and an S&P 500 fund: VTI reaches further down the U.S. market by company size.
VTI's reported average annualized return was 14.7% over the 10 years cited and about 12.6% over the five years cited. Those figures describe past performance. They do not reliably predict future returns. Historical data cited in the article puts the S&P 500's average annual return over the past 98 years at about 10%. Comparing that long historical span with more recent fund returns does not show that VTI will outperform the index going forward.
A broad fund spreads exposure across more U.S. companies. It does not promise higher returns. Smaller stocks may offer more room for growth, but they can also bring more volatility. A total-market fund still concentrates its holdings in the U.S. stock market. Investors should weigh any fund against their time horizon, tolerance for losses and need to diversify beyond domestic stocks. A broad index fund can be a straightforward way to own many companies at once. Recent returns are no reason to assume the next decade will look the same.
