On October 30, 2026, the Dow Jones Industrial Average fell 1.09%, the S&P 500 fell 1.82% and the Nasdaq Composite fell 2.86%. All three went the same way, by amounts ranging from about 1% to almost 3%, because the three indexes hold different companies and count them in different ways. This comparison shows how each is built, works through the arithmetic of the Dow's price weighting with real closing prices, separates the two Nasdaq indexes and explains what each number can and cannot tell you. For the basics of investing in index funds, start with the stocks hub.
How do the Dow, the S&P 500 and the Nasdaq compare?
They differ in how many companies they hold, how those companies are chosen and whether weight comes from share price or from market value.
| Dow Jones Industrial Average | S&P 500 | Nasdaq Composite | Nasdaq-100 | |
|---|---|---|---|---|
| Run by | S&P Dow Jones Indices, with two members from The Wall Street Journal on its committee | S&P Dow Jones Indices | Nasdaq | Nasdaq |
| Starts | May 26, 1896 | Launched March 4, 1957 | February 5, 1971 | January 31, 1985 |
| Members | 30 companies | 500 companies, 503 share lines on September 30, 2026 | About 3,400 securities | About 100 companies |
| How members are chosen | Committee judgment, without numeric rules | Committee applying size, float, trading, profit and US-domicile tests | Every eligible stock listed on Nasdaq, updated daily | The largest non-financial Nasdaq companies, reset each December |
| Weighting | Share price | Market value of publicly tradable shares | Market value of all shares outstanding | Market value, with caps on the largest |
| Financial companies | Included, 26.28% of the index on September 30, 2026 | Included, 11.40% | Included | Excluded |
| Move on October 30, 2026 | −1.09% | −1.82% | −2.86% | −3.46% |
| Price change in 2022 | −8.78% | −19.44% | −33.10% | −32.97% |
| Total return per year, five years to September 30, 2026 | 10.58% | 13.79% | 14.03% | 16.56% |
| What it tells you | How 30 well-known US companies are doing, with the longest history | How large US companies, about 80% of US stock market value, are doing | How the whole Nasdaq-listed market is doing, small companies included | How the biggest non-financial Nasdaq companies are doing, the benchmark QQQ tracks |
The one-day and 2022 moves come from closing levels published by FRED and Yahoo Finance. The five-year returns include dividends and come from the DIA and Invesco fact sheets. None of the headline levels themselves includes dividends.
The S&P 500 and the Nasdaq-100 have their own guides, what is the S&P 500 and what is the Nasdaq-100, which cover their entry rules in detail. The rest of this page concentrates on how the indexes differ from one another.
How does the Dow's price weighting work?
The Dow adds up the share prices of its 30 members and divides the total by a number called the divisor, so higher-priced shares carry more weight.
Dow = sum of the 30 share prices ÷ divisor
S&P Dow Jones Indices does not publish the divisor in a free document, but dividing the sum of the 30 closing prices by the index level recovers it. That gives about 0.168248 at every month-end since June 29, 2026, when Alphabet replaced Verizon, so nothing has changed it since. One dollar of price change in any member therefore moves the Dow 1 ÷ 0.168248, or about 5.94 points, whether the stock costs $40 or $900.
Worked example: What a $10 rise in one stock does to the Dow
Closing prices on October 29, 2026, when the Dow closed at 52,342.56. Every $10 rise adds 10 ÷ 0.168248 = 59.44 points, or 0.114% of the index.
| Stock | Closing price | $10 as a share of its price | Dow points from $10 | Weight in the Dow | Weight in SPY |
|---|---|---|---|---|---|
| Goldman Sachs | $927.73 | 1.08% | 59.44 | 10.53% | 0.41% |
| Nvidia | $213.66 | 4.68% | 59.44 | 2.43% | 7.77% |
| Nike | $38.42 | 26.03% | 59.44 | 0.44% | 0.07% |
A 1% rise tells the story differently: 55.14 Dow points for Goldman Sachs, 12.70 for Nvidia and 2.28 for Nike. In the S&P 500 the same 1% rise in Nvidia would count roughly 19 times as much as one in Goldman Sachs, because Nvidia's company is far larger.
The Dow weights are computed from the closing prices and agree to within 0.01 percentage point with State Street's holdings file for DIA, the Dow ETF, which on that date owned exactly 5,179,069 shares of every member. Holding an equal number of shares is what price weighting means in practice.
No formula decides who gets in. The Dow Jones Averages Methodology says a stock is typically added only if the company has an excellent reputation, shows sustained growth and interests many investors, and the committee also weighs sector balance and the share price itself. Members should be incorporated and headquartered in the US with a plurality of revenue from the US, and transport and utility companies are left to the separate Dow Jones Transportation and Utility Averages. The committee, three people from S&P Dow Jones Indices and two from The Wall Street Journal, monitors whether the highest share price is more than 10 times the lowest. On September 30, 2026, Goldman Sachs at $900.36 was about 25 times Nike at $35.40.
Why does the Dow divisor change?
The divisor changes whenever a stock split, spin-off or membership change would otherwise make the index jump without any change in what the shares are worth.
Worked example: A hypothetical 3-for-1 split in Goldman Sachs
- Before: the 30 prices added up to $8,806.54 on October 29, 2026, with the Dow at 52,342.56, so the divisor was 8,806.54 ÷ 52,342.56 = about 0.168248
- After a 3-for-1 split, Goldman's price falls from $927.73 to $309.24 and the sum to $8,188.05
- To keep the Dow at 52,342.56, the divisor must fall to 8,188.05 ÷ 52,342.56 = about 0.15643
- Goldman's weight drops from 10.53% to 3.78%, and each $1 move in any member now shifts the Dow about 6.39 points
Real changes follow the same logic. When Walmart split its stock 3-for-1 in February 2024, its Dow weight shrank, and S&P Dow Jones Indices responded by adding Amazon in place of Walgreens Boots Alliance on February 26, 2024. On November 8, 2024, Nvidia replaced Intel and Sherwin-Williams replaced Dow Inc. On June 29, 2026, Alphabet's class A shares replaced Verizon, which S&P said made up only about half a percentage point of the index because of its low share price. S&P kept Honeywell in the index through the spin-off of its aerospace business, which was due to complete the same day, and reset the divisor before the open.
Indexes weighted by market value do not need this adjustment for a split, because the share count rises as the price falls and the company's value is unchanged. Stock splits explained covers splits from a shareholder's point of view.
How do market-value weighted indexes differ from the Dow?
In the S&P 500 and both Nasdaq indexes, weight depends on a company's market value, so the largest companies move the index most.
The three versions count market value differently. The S&P 500 uses only shares available to the public, leaving out large holdings by founders, governments or parent companies. The Nasdaq Composite multiplies each price by the total shares outstanding, with no float adjustment. The Nasdaq-100 starts from market value and then caps the largest members, and since May 2026 it has also limited the weight of companies with few tradable shares. Market cap explained covers float in detail.
The result is that the same company can matter very differently. On October 29, 2026, Nvidia, Apple and Microsoft together made up 21.34% of SPY but 12.40% of DIA, while Goldman Sachs and Caterpillar, two of the Dow's highest-priced stocks, made up 17.88% of DIA and 0.85% of SPY. Overlap is complete in one direction: all 30 Dow stocks were in SPY, accounting for 39.15% of the fund, or 41.16% once Alphabet's class C shares, which the Dow does not hold, are added. Nine of them, including Apple, Amazon, Microsoft, Nvidia and Walmart, were also in the Nasdaq-100.
What is the difference between the Nasdaq Composite and the Nasdaq-100?
The Composite holds every eligible common stock listed on Nasdaq, about 3,400 securities, while the Nasdaq-100 keeps only the 100 largest non-financial companies and caps their weights.
The Composite has almost no entry tests. Its methodology sets no minimum size, trading volume, float, sector or country; a security needs only to be listed on Nasdaq, be an eligible type such as common stock or an American depositary receipt, and have traded for one day. The list is rebuilt daily. Funds, preferred shares, warrants and rights are excluded. That breadth takes in banks, small biotech companies and recent IPOs that the Nasdaq-100 leaves out, though market-value weighting means the giants dominate both.
| Total return to September 30, 2026 | Nasdaq Composite | Nasdaq-100 |
|---|---|---|
| 1 year | 19.25% | 24.00% |
| 3 years, per year | 27.52% | 28.31% |
| 5 years, per year | 14.03% | 16.56% |
| 2023 | 44.64% | 55.13% |
| 2024 | 29.57% | 25.88% |
Figures from Invesco's fact sheets for its Nasdaq-100 ETFs, which report both indexes. The two can swap places from year to year, as 2023 and 2024 show. They also fell together in the dot-com crash: the Composite closed at 5,048.62 on March 10, 2000, dropped 77.9% to 1,114.11 by October 9, 2002 and did not close above its old peak until April 23, 2015. The Nasdaq-100 guide covers its own drop of 82.9% over the same period.
What does each index tell you?
Each one answers a different question, so the useful one depends on what you want to know.
- The Dow shows how 30 large, well-known US companies are doing, with a record back to 1896. Because of price weighting and its small size, it is a rough gauge of the market, and its biggest weights in late 2026 were a bank and a machinery maker rather than the largest US companies.
- The S&P 500 is the closest of the three to a measure of large US companies as a whole, covering about 80% of US stock market value. It is the index that funds such as SPY copy, and index funds explained shows how such funds work.
- The Nasdaq Composite tracks the companies that chose to list on Nasdaq. It leans toward technology and includes thousands of small companies, so it is not a measure of the whole market.
- The Nasdaq-100 follows the largest non-financial companies on Nasdaq and is the benchmark for QQQ.
Read moves in percentages, not points. The levels have nothing in common: the Dow's is inflated by its small divisor, while the S&P 500 and the Nasdaq Composite started from their own base values decades apart. A 500-point fall is about 1% of a Dow near 52,000 but 6.6% of an S&P 500 near 7,600, so a headline in points without a percentage says little.
Worked example: Points versus percent on October 30, 2026
- Dow: 52,342.56 to 51,770.31, down 572.25 points, or 1.09%
- S&P 500: 7,720.39 to 7,580.07, down 140.32 points, or 1.82%
- Nasdaq Composite: 26,184.72 to 25,437.00, down 747.72 points, or 2.86%
The S&P 500 lost the fewest points of the three yet fell further than the Dow in percentage terms, which is why point counts mislead.
Remember too that the quoted levels leave out dividends. DIA's fact sheet put the Dow's dividend yield at 1.55% on September 30, 2026, income that a price chart never shows.
What are the risks of judging the market by one index?
The main risk is treating a narrow or oddly weighted measure as the whole market and making decisions on that basis.
- A small sample. The Dow's 30 companies made up about 41% of SPY's value on October 29, 2026, so most of the market sits outside it, and its weights follow share prices rather than company size.
- Concentration. Both Nasdaq indexes lean heavily toward technology. The Composite lost 33.10% in 2022 and 77.9% from 2000 to 2002, far more than the S&P 500 in either period.
- Gaps in coverage. The Dow and the S&P 500 leave out small companies, the Nasdaq indexes leave out companies listed on the NYSE, and none of them covers markets outside the US. International stocks for US investors covers that part of a portfolio.
- Rules that change. S&P changed the Dow's membership in February 2024, November 2024 and June 2026, and Nasdaq rewrote the Nasdaq-100 rules in May 2026, so long histories mix companies and rules that no longer apply.
- No guarantee. Funds that track any of these indexes can fall sharply, as in 2022, and the returns above describe the past only. Bear markets and corrections shows how long past declines took to recover.