Markets
What is a Stock Market Index?
What is a Stock Market Index?
“How did the stock market do today?”
At surface, this seems like a simple question – but it’s also deceptively difficult to answer. The market can be defined as many different things, and there are actually over 100,000 publicly traded companies in the world to choose from.
Luckily, the use of a stock market index can help define a particular market, as well as track its performance in a way that is easy to reference.
Types of Indices
Today’s infographic from StocksToTrade.com defines a stock market index as a thermometer that measures the health of a group of stocks. When this particular group of stocks changes in value, the index follows it along.
A stock market index can track a group of stocks based on several different factors:
Global: Some indices, such as the MSCI All-Country World Index, aim to be a proxy for all global equities.
Regional Geography: A stock market index can also track a specific region, such as Europe. As an example, the EURO STOXX 50 tracks the performance of the largest and most liquid 50 stocks in the Eurozone.
National: Indices can also serve as a proxy for the performance of an entire country’s equities. The FTSE 100 in the United Kingdom tracks the 100 largest companies traded, which total to 81% of the total market capitalization of the exchange.
Industry: A stock market index can try to track the performance of an industry as a whole. The GDXJ, for example, is an ETF based on an underlying index that tracks the performance of smallcap mining companies focused on gold and silver.
Exchange: Indices also are used for specific exchanges. The S&P/TSX Venture Composite Index, for example, is used to represent the performance of companies that trade on the TSX Venture exchange in Canada.
Main Indices in the U.S.
Last year we did a graphical primer of the differences between the main indices and exchanges in the U.S., but we’ll summarize the major indices here as well.
S&P 500: First calculated in 1923, the S&P 500 covers the largest companies on the NYSE and Nasdaq exchanges in the United States, and represents $21.4 trillion in value.
Dow Jones Industrial Average: The DJIA is a price-weighted index of 30 significant companies traded on the NYSE and Nasdaq. It has a market capitalization of approximately $6 trillion, and was founded back in 1885.
Nasdaq Composite: Used more as a proxy for the technology industry, this index tracks 3,000 equities on the Nasdaq exchange, worth $6.8 trillion. It does include some companies not located in the U.S.
Interested in learning more about exchanges and indices? See the 20 largest stock exchanges in the world.
Markets
3 Reasons Why AI Enthusiasm Differs from the Dot-Com Bubble
Valuations are much lower than they were during the dot-com bubble, but what else sets the current AI enthusiasm apart?

3 Reasons Why AI Enthusiasm Differs from the Dot-Com Bubble
Artificial intelligence, like the internet during the dot-com bubble, is getting a lot of attention these days. In the second quarter of 2023, 177 S&P 500 companies mentioned “AI” during their earnings call, nearly triple the five-year average.
Not only that, companies that mentioned “AI” saw their stock price rise 13.3% from December 2022 to September 2023, compared to 1.5% for those that didn’t.
In this graphic from New York Life Investments, we look at current market conditions to find out if AI could be the next dot-com bubble.
Comparing the Dot-Com Bubble to Today
In the late 1990s, frenzied optimism for internet-related stocks led to a rapid rise in valuations and an eventual market crash in the early 2000s. By the time the market hit rock bottom, the tech-heavy Nasdaq 100 Index had dropped 82% from its peak.
The growing enthusiasm for AI has some concerned that it could be the next dot-com bubble. But here are three reasons that the current environment is different.
1. Valuations Are Lower
Stock valuations are much lower than they were at the peak of the dot-com bubble. For example, the forward price-to-earnings ratio of the Nasdaq 100 is significantly lower than it was in 2000.
Date | Forward P/E Ratio |
---|---|
March 2000 | 60.1x |
November 2023 | 26.4x |
Lower valuations are an indication that investors are putting more emphasis on earnings and stocks are less at risk of being overvalued.
2. Investors Are More Hesitant
During the dot-com bubble, flows to equity funds increased by 76% from 1999 to 2000.
Year | Combined ETF and Mutual Fund Flows to Equity Funds |
---|---|
1997 | $231B |
1998 | $163B |
1999 | $200B |
2000 | $352B |
2001 | $63B |
2002 | $14B |
Source: Investment Company Institute
In contrast, equity fund flows have been negative in 2022 and 2023.
Year | Combined ETF and Mutual Fund Flows to Equity Funds |
---|---|
2021 | $295B |
2022 | -$54B |
2023* | -$137B |
Source: Investment Company Institute
*2023 data is from January to September.
Based on fund flows, investors appear hesitant of stocks, rather than overly exuberant.
3. Companies Are More Established
Leading up to the internet bubble, the number of technology IPOs increased substantially.
Year | Number of Technology IPOs | Median Age |
---|---|---|
1997 | 174 | 8 |
1998 | 113 | 7 |
1999 | 370 | 4 |
2000 | 261 | 5 |
2001 | 24 | 9 |
2002 | 20 | 9 |
Many of these companies were relatively new and, at the peak of the bubble in 2000, only 14% of them were profitable.
In recent years, there have been far fewer tech IPOs as companies wait for more positive market conditions. And those that have gone public, the median age is much higher.
Year | Number of Technology IPOs | Median Age |
---|---|---|
2020 | 48 | 12 |
2021 | 126 | 12 |
2022 | 6 | 15 |
Ultimately, many of the companies benefitting from AI are established companies that are already publicly traded. New, unproven companies are much less common in public markets.
Navigating Modern Tech Amid Dot-Com Bubble Worries
Valuations, equity flows, and the shortage of tech IPOs all suggest that AI is different than the dot-com bubble.
However, risk is still present in the market. For instance, only 33% of tech companies that went public in 2022 were profitable. Investors can help manage their risk by keeping a diversified portfolio rather than choosing individual stocks.

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