Stock market index

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A comparison of three major U.S. stock indices: the NASDAQ Composite, Dow Jones Industrial Average, and S&P 500 Index. All three have the same height at March 2007. The NASDAQ spiked during the dot-com bubble in the late 1990s, a result of the large number of technology companies on that index. Comparison of three stock indices after 1975.svg
A comparison of three major U.S. stock indices: the NASDAQ Composite, Dow Jones Industrial Average, and S&P 500 Index. All three have the same height at March 2007. The NASDAQ spiked during the dot-com bubble in the late 1990s, a result of the large number of technology companies on that index.

In finance, a stock index, or stock market index, is an index that measures the performance of a stock market, or of a subset of a stock market. It helps investors compare current stock price levels with past prices to calculate market performance. [1]

Contents

Two of the primary criteria of an index are that it is investable and transparent: [2] The methods of its construction are specified. Investors may be able to invest in a stock market index by buying an index fund, which is structured as either a mutual fund or an exchange-traded fund, and "track" an index. The difference between an index fund's performance and the index, if any, is called tracking error .

Types of indices by coverage

Stock market indices may be classified and segmented by the set of underlying stocks included in the index, sometimes referred to as the "coverage". The underlying stocks are typically grouped together based on their underlying economics or underlying investor demand that the index is seeking to represent or track.

The coverage of a stock market index is separate from the weighting method. For example, the S&P 500 market-cap weighted index covers the 500 largest stocks from the S&P Total Market Index, but an equally weighted S&P 500 index is also available with the same coverage.

World or global coverage
These indices attempt to represent the performance of the global stock market.[ citation needed ] The MSCI World has nearly 1,400 constituents that cover approximately 85% of the free float-adjusted market capitalization in 23 developed countries. [3] The FTSE Global Equity Index Series goes further down the market capitalization spectrum by including over 16,000 companies. [4] The By contrast, the S&P Global 100 is more limited with only 100.
Regional coverage
These indices represent the performance of the stock market of a single geographical region. Some examples of these indices are the FTSE Developed Europe Index, and the FTSE Developed Asia Pacific Index.
Country coverage
These indices represent the performance of the stock market of a single country—and by proxy, reflects investor sentiment on the state of its economy. The most frequently quoted market indices are national indices composed of the stocks of large companies listed on a nation's largest stock exchanges, such as the S&P 500 Index in the United States, the Nikkei 225 in Japan, the DAX in Germany, the NIFTY 50 in India, and the FTSE 100 in the United Kingdom.
Exchange-based coverage
These indices may be based on the exchange on which the stocks are traded, such as the NASDAQ-100, or groups of exchanges, such as the Euronext 100 or OMX Nordic 40.
Sector-based coverage
These indices track the performance of specific market sectors. Some examples are the Wilshire US REIT Index, which tracks more than 80 real estate investment trusts, and the NASDAQ Biotechnology Index which consists of about 200 firms in the biotechnology industry.

Types of indices by weighting method

S&P BSE SENSEX chart.svg
Chart of S&P BSE SENSEX Index monthly data from August 2, 1995, to August 2, 2017. The SENSEX represents the top 30 companies by market cap.
NIFTY 50 Returns Graph.png
National Stock Exchange of India from 2000 to 2020. (Indices NIFTY 50). The NIFTY 50 represents the top 50 companies by market cap.

Stock market indices may be categorized by their index weight methodology, or the rules on how stocks are allocated in the index, independent of its stock coverage. For example, the S&P 500 and the S&P 500 Equal Weight each cover the same group of stocks, but the S&P 500 is weighted by market capitalization, while the S&P 500 Equal Weight places equal weight on each constituent. Some common index weighting methods are listed below. In practice, many indices will impose constraints, such as concentration limits, on these rules. [5] : 14 

Market-capitalization weighting
This method weights constituent stocks by their market capitalization (often shortened to "market cap"), i.e. the stock price multiplied by the number of shares outstanding. Under the capital asset pricing model, a market-cap weighted market portfolio (which could be approximated by a market-cap weighted equity index portfolio) is mean-variance efficient, meaning that it can be expected to produce the highest available return for a given level of risk. A market-cap weighted index might also be thought of as a liquidity-weighted index, since the largest-cap stocks tend to have the highest liquidity and the greatest capacity to handle investor flows; portfolios with such stocks could have very high investment capacity. [5] : 7 
Free-float adjusted market-capitalization weighting
This method adjusts each company's market-cap index weight by excluding closely or strategically held shares that are not generally available to the public market. Such shares may be held by governments, affiliated companies, founders, and employees. Foreign ownership limits imposed by government regulation could also be subject to free-float adjustments. These adjustments inform investors of potential liquidity issues from these holdings that are not apparent from the raw number of a stock's shares outstanding. Free-float adjustments are not easy to calculate, and different index providers have different free-float adjustment methods, which could sometimes produce different results. [5] : 7  [6] : 1264 
Price weighting
This method weights each constituent stock by its price per share divided by the sum of all share prices in the index. A price-weighted index can be thought of as a portfolio with one share of each constituent stock. However, a stock split for any constituent stock of the index would cause the weight in the index of the stock that split to decrease, even in the absence of any meaningful change in the fundamentals of that stock. This feature makes price-weighted indices unattractive as benchmarks for passive investment strategies and portfolio managers. Nonetheless, many price-weighted indices, such as the Dow Jones Industrial Average and the Nikkei 225, are followed widely as visible indicators of day-to-day market movements. [5] : 7 
Equal weighting
This method gives each constituent stocks weights of 1/n, where n represents the number of stocks in the index. This method produces the least-concentrated portfolios. Equal weighting of stocks in an index is considered a naive strategy because it does not show preference towards any single stock. Zeng and Luo (2013) notes that broad market equally weighted indices are factor-indifferent and randomizes factor mispricing. Equal weight stock indices tend to overweight small-cap stocks and to underweight large-cap stocks compared to a market-cap weighted index. These biases usually result in higher volatility and lower liquidity than market-cap weight indices. [5] : 7–8  [7] [8] For example, the Barron's 400 Index assigns an equal value of 0.25% to each of the 400 stocks included in the index, which together add up to the 100% whole. [9]
Fundamental factor weighting
This method, also known as fundamentally based indexes, weights constituent stocks based on arbitrarily selected "stock fundamental factors" rather stock financial market data. Fundamental factors could include sales, income, dividends, and other factors analyzed in fundamental analysis. Similar to fundamental analysis, fundamental weighting assumes that stock market prices will converge to an intrinsic price implied by fundamental attributes. Certain fundamental factors are also used in generic factor weighting indices. [5] : 8 
Factor weighting
This method weights constituent stocks based on market risk factors of stocks as measured in the context of factor models, such as the Fama–French three-factor model. Such factors commonly include Growth, Value, Size, Yield, Momentum, Quality, and Volatility. Passive factor investing strategies are sometimes known as "smart beta" strategies. Investors could use factor investment strategies or portfolios to complement a market-cap weighted indexed portfolio by tilting or changing their portfolio exposure to certain factors. [5] : 11–13 
Volatility weighting
This method weights constituent stocks by the inverse of their relative price volatility. Price volatility is defined differently by each index provider, but two common methods are the standard deviation of the past 252 trading days (approximately one calendar year), and the weekly standard deviation of price returns for the past 156 weeks (approximately three calendar years). [5] : 14 
Minimum variance weighting
This method weights constituent stocks using a mean-variance optimization process. In a volatility weighted index, highly volatile stocks are given less weight in the index, while in a minimum variance weighting index, highly volatile stocks that are negatively correlated with the rest of the index can be given relatively larger weights than they would be given in the volatility weighted index. [5] : 14 

Presentation of index returns

Some indices, such as the S&P 500 Index, have multiple versions. [10] These versions can differ based on how the index components are weighted and on how dividends are accounted. For example, there are three versions of the S&P 500 Index: price return, which only considers the price of the components, total return, which accounts for dividend reinvestment, and net total return, which accounts for dividend reinvestment after the deduction of a withholding tax. [10]

The Wilshire 4500 and Wilshire 5000 indices have five versions each: full capitalization total return, full capitalization price, float-adjusted total return, float-adjusted price, and equal weight. The difference between the full capitalization, float-adjusted, and equal weight versions is in how index components are weighted. [11] [12]

Criticism of capitalization-weighting

One argument for capitalization weighting is that investors must, in aggregate, hold a capitalization-weighted portfolio anyway. This then gives the average return for all investors; if some investors do worse, other investors must do better (excluding costs). [13]

Indices and passive investment management

Passive management is an investing strategy involving investing in index funds, which are structured as mutual funds or exchange-traded funds that track market indices. [14] The SPIVA (S&P Indices vs. Active) annual "U.S. Scorecard", which measures the performance of indices versus actively managed mutual funds, finds the vast majority of active management mutual funds underperform their benchmarks, such as the S&P 500 Index, after fees. [15] [16]

Unlike a mutual fund, which is priced daily, an exchange-traded fund is priced continuously and is optionable. [17]

Ethical stock market indices

Several indices are based on ethical investing, and include only companies that meet certain ecological or social criteria, such as the Calvert Social Index, Domini 400 Social Index, FTSE4Good Index, Dow Jones Sustainability Index, STOXX Global ESG Leaders Index, several Standard Ethics Aei indices, and the Wilderhill Clean Energy Index. [18] Other ethical stock market indices may be based on diversity weighting (Fernholz, Garvy, and Hannon 1998). In 2010, the Organization of Islamic Cooperation announced the initiation of a stock index that complies with Sharia's ban on alcohol, tobacco and gambling. [19]

Critics of such initiatives argue that many firms satisfy mechanical "ethical criteria" (e.g. regarding board composition or hiring practices) but fail to perform ethically with respect to shareholders (e.g. Enron). Indeed, the seeming "seal of approval" of an ethical index may put investors more at ease, enabling scams. One response to these criticisms is that trust in the corporate management, index criteria, fund or index manager, and securities regulator, can never be replaced by mechanical means, so "market transparency" and "disclosure" are the only long-term-effective paths to fair markets. From a financial perspective, it is not obvious whether ethical indices or ethical funds will out-perform their more conventional counterparts. Theory might suggest that returns would be lower since the investible universe is artificially reduced and with it portfolio efficiency. (It conflicts with the Capital Asset Pricing Model, see above.) On the other hand, companies with good social performances might be better run, have more committed workers and customers, and be less likely to suffer reputation damage from incidents (oil spillages, industrial tribunals, etc.) and this might result in lower share price volatility, [20] although such features, at least in theory, will have already been factored into the market price of the stock. The empirical evidence on the performance of ethical funds and of ethical firms versus their mainstream comparators is very mixed for both stock [21] [22] and debt markets. [23]

See also

Related Research Articles

Passive management is an investing strategy that tracks a market-weighted index or portfolio. Passive management is most common on the equity market, where index funds track a stock market index, but it is becoming more common in other investment types, including bonds, commodities and hedge funds.

<span class="mw-page-title-main">CAC 40</span> Blue chip stock market index

The CAC 40 is a benchmark French stock market index. The index represents a capitalization-weighted measure of the 40 most significant stocks among the 100 largest market caps on the Euronext Paris. It is a price return index. It is one of the main national indices of the pan-European stock exchange group Euronext alongside Euronext Amsterdam's AEX, Euronext Brussels' BEL20, Euronext Dublin's ISEQ 20, Euronext Lisbon's PSI-20 and the Oslo Bors OBX Index. It is an index without dividends. Cotation operates every working day from 9:00 a.m. to 5:30 p.m. It is updated every 15 seconds.

<span class="mw-page-title-main">S&P 500</span> American stock market index

The Standard and Poor's 500, or simply the S&P 500, is a stock market index tracking the stock performance of 500 of the largest companies listed on stock exchanges in the United States. It is one of the most commonly followed equity indices and includes approximately 80% of the total market capitalization of U.S. public companies, with an aggregate market cap of more than $43 trillion as of January 2024.

<span class="mw-page-title-main">Wilshire 5000</span> Stock market index

The Wilshire 5000 Total Market Index, or more simply the Wilshire 5000, is a market-capitalization-weighted index of the market value of all American stocks actively traded in the United States. As of December 31, 2023, the index contained 3,403 components. The index is intended to measure the performance of most publicly traded companies headquartered in the United States, with readily available price data. Hence, the index includes a majority of the common stocks and REITs traded primarily through New York Stock Exchange, NASDAQ, or the American Stock Exchange. Limited partnerships and ADRs are not included. It can be tracked by following the ticker ^FTW5000.

The IBEX 35 is the benchmark stock market index of the Bolsa de Madrid, Spain's principal stock exchange. Initiated in 1992, the index is administered and calculated by Sociedad de Bolsas, a subsidiary of Bolsas y Mercados Españoles (BME), the company which runs Spain's securities markets. It is a market capitalization weighted index comprising the 35 most liquid Spanish stocks traded in the Madrid Stock Exchange General Index and is reviewed twice annually. Trading on options and futures contracts on the IBEX 35 is provided by MEFF, another subsidiary of BME.

The Bovespa Index, best known as Ibovespa is the benchmark index of about 86 stocks traded on the B3, accounting for the majority of trading and market capitalization in the Brazilian stock market. It is a weighted measurement index.

<span class="mw-page-title-main">Russell 2000 Index</span> US small-cap stock market index

The Russell 2000 Index is a small-cap U.S. stock market index that makes up the smallest 2,000 stocks in the Russell Index. It was started by the Frank Russell Company in 1984. The index is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group (LSEG).

Russell indexes are a family of global stock market indices from FTSE Russell that allow investors to track the performance of distinct market segments worldwide. Many investors use mutual funds or exchange-traded funds based on the FTSE Russell Indexes as a way of gaining exposure to certain portions of the U.S. stock market. Additionally, many investment managers use the Russell Indexes as benchmarks to measure their own performance. Russell's index design has led to more assets benchmarked to its U.S. index family than all other U.S. equity indexes combined.

The EURO STOXX 50 is a stock index of Eurozone stocks designed by STOXX, an index provider owned by Deutsche Börse Group. The index is composed of 50 stocks from 11 countries in the Eurozone.

The S&P/ASX 200 (XJO) index is a market-capitalisation weighted and float-adjusted stock market index of stocks listed on the Australian Securities Exchange. The index is maintained by Standard & Poor's and is considered the benchmark for Australian equity performance. It is based on the 200 largest ASX listed stocks, which together account for about 82% of Australia's share market capitalisation.

A capitalization-weightedindex, also called a market-value-weighted index is a stock market index whose components are weighted according to the total market value of their outstanding shares. Every day an individual stock's price changes and thereby changes a stock index's value. The impact that individual stock's price change has on the index is proportional to the company's overall market value, in a capitalization-weighted index. In other types of indices, different ratios are used.

<span class="mw-page-title-main">Swiss Market Index</span> Blue-chip stock market index of Switzerland

The Swiss Market Index (SMI) is Switzerland's blue-chip stock market index, which makes it the most followed in the country. It is made up of 20 of the largest and most liquid Swiss Performance Index (SPI) stocks. As a price index, the SMI is not adjusted for dividends.

Fundamentally based indexes or fundamental indexes, also called fundamentally weighted indexes, are indexes in which stocks are weighted according to factors related to their fundamentals such as earnings, dividends and assets, commonly used when performing corporate valuations. This fundamental weight may be calculated statically, or it may be adjusted by the security's fundamental to market capitalization ratio to further neutralize the price factor between different securities. Indexes that use a composite of several fundamental factors attempt to average out sector biases that may arise from relying on a single fundamental factor. A key belief behind the fundamental index methodology is that underlying corporate accounting/valuation figures are more accurate estimators of a company's intrinsic value, rather than the listed market value of the company, i.e. that one should buy and sell companies in line with their accounting figures rather than according to their current market prices. In this sense fundamental indexing is linked to so-called fundamental analysis.

The CBV-Index, or Corporates and Businesses of Vietnam Index, is a market index containing the stocks of 50 leading corporations of Vietnam. Subsets of this index include the CBV 10 and CBV 20.

The S&P/ASX 300, or simply, ASX 300, is a stock market index of Australian stocks listed on the Australian Securities Exchange (ASX). The index is market-capitalisation weighted, meaning each company included is in proportion to the indexes total market value, and float-adjusted, meaning the index only considers shares available to public investors.

The TA-125 Index, typically referred to as the Tel Aviv 125 and formerly the TA-100 Index, is a stock market index of the 125 most highly capitalised companies listed on the Tel Aviv Stock Exchange (TASE). The index began on 1 January 1992 with a base level of 100. The highest value reached to date is 2152.16, in January 2022. On 12 February 2017, the index was expanded to include 125 instead of 100 stocks, in an attempt to improve stability and therefore reduce risk for trackers and encourage foreign investment.

The PSI-20 is a benchmark stock market index of companies that trade on Euronext Lisbon, the main stock exchange of Portugal. The index tracks the prices of the twenty listings with the largest market capitalisation and share turnover in the PSI Geral, the general stock market of the Lisbon exchange. It is one of the main national indices of the pan-European stock exchange group Euronext alongside Brussels' BEL20, Paris's CAC 40 and Amsterdam's AEX. On August 12, 2021 index has been renamed from PSI-20 to PSI.

VN30 Equal Weight Index tracks the total performance of the top 30 large-cap, liquid stocks listed on the Ho Chi Minh City stock exchange along with two popular indices in Vietnam: VN Index and VN30 Index. All index constituents are equal-weighted to help investors deal with liquidity, foreign ownership and state-owned enterprise constraints when investing in Vietnam.

References

  1. ↑ Caplinger, Dan (January 18, 2020). "What Is a Stock Market Index?". The Motley Fool .
  2. ↑ Lo, Andrew W. (2016). "What Is an Index?". Journal of Portfolio Management. 42 (2): 21–36. doi:10.3905/jpm.2016.42.2.021. hdl: 1721.1/109050 . S2CID   219222815.
  3. ↑ "MSCI World Index". MSCI.com. Retrieved December 30, 2024.
  4. ↑ "FTSE Global Equity Index Series (GEIS)". FTSE Russell . Retrieved February 19, 2023.
  5. 1 2 3 4 5 6 7 8 9 Smith, David M.; Yousif, Kevin K. "Passive Equity Investing" . CFA Institute.
  6. ↑ Hirst, Scott; Kastiel, Kobi (May 1, 2019). "Corporate Governance by Index Exclusion". Boston University Law Review. 99 (3): 1229.
  7. ↑ Edwards, Tim; Lazzara, Craig J. (May 2014). "Equal-Weight Benchmarking: Raising the Monkey Bars" (PDF). S&P Global.
  8. ↑ "Practice Essentials – Equal Weight Indexing" (PDF). S&P Dow Jones Indices.
  9. ↑ Fabian, David (November 14, 2014). "Checking In on Equal-Weight ETFs This Year". Benzinga.
  10. 1 2 "Methodology Matters". US.Spindicies.com. S&P Dow Jones Indices. Retrieved September 25, 2023.
  11. ↑ "Indexes". Wilshire Associates.
  12. ↑ "Wilshire 4500 Completion Index". Wilshire Associates. Archived from the original on June 14, 2021. Retrieved March 22, 2023.
  13. ↑ Sharpe, William F. (May 2010). "Adaptive Asset Allocation Policies". Financial Analysts Journal. 66 (3). CFA Institute: 45–59. doi:10.2469/faj.v66.n3.3. S2CID   155081123.
  14. ↑ Schramm, Michael (September 27, 2019). "What Is Passive Investing?". Morningstar, Inc.
  15. ↑ "SPIVA U.S. Score Card". S&P Dow Jones Indices.
  16. ↑ Thune, Kent (July 3, 2019). "Why Index Funds Beat Actively Managed Funds". Dotdash .
  17. ↑ Chang, Ellen (May 21, 2019). "How to Choose Between ETFs and Mutual Funds". U.S. News & World Report .
  18. ↑ Divine, John (February 15, 2019). "7 of the Best Socially Responsible Funds". U.S. News & World Report.
  19. ↑ Haris, Anwar (November 25, 2010). "Muslim-Majority Nations Plan Stock Index to Spur Trade: Islamic Finance". Bloomberg L.P.
  20. ↑ Oikonomou, Ioannis; Brooks, Chris; Pavelin, Stephen (2012). "The Impact of Corporate Social Performance on Financial Risk and Utility: A Longitudinal Analysis" (PDF). Financial Management. 41 (2): 483–515. doi:10.1111/j.1755-053X.2012.01190.x. ISSN   1755-053X. S2CID   154707419.
  21. ↑ Brammer, Stephen; Brooks, Chris; Pavelin, Stephen (2009). "The Stock Performance of America's 100 Best Corporate Citizens" (PDF). The Quarterly Review of Economics and Finance. 49 (3): 1065–1080. doi:10.1016/j.qref.2009.04.001. ISSN   1062-9769.
  22. ↑ Brammer, Stephen; Brooks, Chris; Pavelin, Stephen (2006). "Corporate social performance and stock returns: UK evidence from disaggregate measures" (PDF). Financial Management. 35 (3): 97–116. doi:10.1111/j.1755-053X.2006.tb00149.x. ISSN   1755-053X. S2CID   53399394.
  23. ↑ Oikonomou, Ioannis; Brooks, Chris; Pavelin, Stephen (2014). "The Effects of Corporate Social Performance on the Cost of Corporate Debt and Credit Ratings" (PDF). Financial Review. 49 (1): 49–75. doi:10.1111/fire.12025. ISSN   1540-6288. S2CID   154436407.
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