What is the stock market index?

In the stock market, shares of many companies are traded. The stock market index functions as a benchmark for assessing the overall state of the market and is essentially an average of the prices of all listed stocks in a given market. Simply put, a rise in the stock market index indicates an increase in the average price of shares in the market. There are various methods for calculating a stock market index. In the past, the Tehran Stock Exchange index was calculated based on a weighted average. In this method, the price of each share was multiplied by the share of that company in the overall market.
In general, the current stock market index in the Tehran Stock Exchange is a type of weighted return index. In this calculation model, although the prices of some companies' shares may decline, if smaller companies perform positively, the overall weighted average of the index may still drop. This is because larger companies carry more weight in the index calculation, and their price changes have a greater impact on the index.
The Tehran Stock Exchange All Share Index (TEDPIX) is a benchmark for measuring the average price changes and cash dividends of listed companies, such that the return of a stock portfolio composed of all companies, weighted accordingly, will exactly match the changes in TEDPIX.On July 14, 2025, this index reached 2,734,000 points, indicating a 2.86% increase compared to the previous day.
As of the beginning of 2025, the total market capitalization of the Tehran Stock Exchange was approximately$120 billion, and the P/E ratio stood at 7.86 as recorded in June 2024.
The highest historical record of TEDPIX was registeredon April 27, 2023, at 2,479,340 points.
Large companies such as Persian Gulf Petrochemical and Mobarakeh Steel have a significant impact on index fluctuations due to their heavy weighting in the calculations, and price changes in these companies can noticeably shift the overall movement of TEDPIX.

What Is the Stock Market Index?

A stock market index is essentially a numerical value that measures price fluctuations in the stock market and indicates whether share prices are rising or falling. In the stock market, there are various indices, each calculated using its own specific formula; however, their shared goal is to measure the overall market condition. These indices help investors analyze the general market trend and price movements, enabling them to make better informed decisions regarding buying and selling stocks.

Stock Market Index Calculation Formula

Index Value = (Current Market Value of Stocks at Time of Calculation / Market Value of Stocks at Base Time) × 100

How to View Different Stock Market Indices

The All Share Index and other market indices can be viewed on the homepage of the TSETMC website. Additionally, you can access both the numerical values and charts of the All Share Index through your brokerage’s online trading platform.

Types of Stock Market Indices Around the World

Globally, there are numerous stock market indices, each designed for specific purposes. These indices enable investors and analysts to evaluate and compare the performance of various markets. Below are some of the most well known global stock indices:

S&P 500

This is one of the most reputable stock indices in the United States, tracking the performance of 500 large American companies. The companies within this index are weighted based on market capitalization. The S&P 500 is widely regarded as a benchmark for assessing the overall state of the U.S. economy, and many investment funds follow this index.

Dow Jones Industrial Average (DJIA)

The Dow Jones is one of the oldest and most recognized stock indices in the world, representing the performance of 30 large and stable U.S. companies. It is a price weighted index, meaning that companies with higher share prices have a greater impact on the index. The Dow is often cited in financial news as a representation of the broader U.S. stock market.

Nasdaq Composite

The Nasdaq index includes more than 3,000 companies, primarily active in technology and related industries. Due to its focus on tech oriented companies, it is considered a key benchmark for evaluating the performance of the technology sector. Major global companies such as Apple, Microsoft, and Amazon are included in this index.

Nikkei 225

This index represents the Japanese stock market and includes 225 leading Japanese companies. The Nikkei is also a price weighted index, where stock price movements have a direct effect on the index value.

Regional and National Indices

In addition to global indices, many countries and geographic regions have their own specific indices. For example, the FTSE 100 in the UK reflects the performance of the 100 largest listed companies in the country, while the DAX index represents the German stock market. These indices help both local and international investors understand the economic and financial condition of a specific country or region.

Sector Specific Indices

There are indices dedicated to specific industries or groups of companies. For instance, the Nasdaq 100 focuses solely on the 100 largest tech companies. Additionally, indices such as the Energy Index or the Financial Index reflect the performance of particular sectors of the economy.

Global and Multinational Indices

Some indices track the performance of multinational companies on a global scale. For example, the MSCI World Index comprises a collection of companies from various countries and provides a broad overview of the global economy.
Stock market indices are vital tools for analyzing financial markets. They allow investors to grasp market trends or sector specific dynamics without having to analyze individual stocks. Different calculation methodologies such as market cap weighted, price weighted, and equal weighted indices offer diverse perspectives on market performance. Global indices like the S&P 500, Dow Jones, and Nasdaq, alongside regional and sector based indices, play a crucial role in investment decision making and economic analysis.

Market Indices Based on Company Size

In many stock markets, there are indices specifically categorized by company size. These indices help investors evaluate the performance of large cap, mid cap, and small cap companies separately and develop appropriate investment strategies for each group.

Large Cap Companies

Indices that track large cap companies typically include firms with high market capitalization. These companies are often more stable, generate steady income, and involve lower investment risk. A prominent example is the S&P 500, which covers 500 of the largest publicly traded U.S. companies.

Mid Cap Companies

These indices are designed to monitor medium sized companies. Mid cap firms generally offer more flexibility compared to large corporations and can experience significant growth. One of the most well known indices in this category is the S&P MidCap 400.

Small Cap Companies

Small cap indices focus on companies with relatively low market capitalization. These firms are usually in early growth stages, offering high long term growth potential but also carry higher risk. The Russell 2000 is one of the most recognized indices tracking the performance of 2,000 small cap companies.
Investing based on company size requires different strategies. For instance, risk tolerant investors may prefer small cap companies due to their higher potential returns. In contrast, those seeking greater security might focus on large cap firms.
Using these indices allows investors to diversify their portfolios and manage risk more effectively.

Stock Market Indices as a Measure of Economic Health

The table below outlines the roles and applications of stock market indices as a measure of economic health:

Stock market indices not only reflect the state of the equity market but also serve as a powerful tool for assessing the overall health of the economy.
Changes in indices often mirror a country’s economic conditions, and analyzing them can provide valuable insights into the current status and future outlook of the economy.

Economic Growth or Recession

Stock market indices often serve as indicators of economic growth or recession. A sustained rise in indices reflects investor confidence in the economy and corporate growth, while a continuous decline may signal an impending economic downturn.

Overall Picture of Economic Sectors

Specialized indices such as the Energy Index or Financial Index highlight the performance of specific sectors of the economy. For example, an increase in the Financial Index may indicate improved credit conditions and a rise in banking activities.

Influence on Economic Policies

Governments and central banks use stock market indices as one of the tools to assess the state of the economy. For instance, if indices consistently decline, policymakers may implement measures such as interest rate cuts or stimulus packages to support the economy.

Investor Confidence

Stock market indices reflect the level of investor confidence in the economy. If the indices are rising, it indicates strong market and economic confidence, whereas a decline may suggest reduced confidence and growing concerns.

Forecasting Long Term Trends

Analyzing index behavior over extended periods can help predict economic trends. For example, a long term upward trend in stock indices may signal a movement toward economic stability and development.
Stock market indices ranging from specialized indices to those based on company size are vital tools for investors and analysts. These indices not only assist investors in evaluating market performance and shaping their strategies, but also function as a key benchmark for assessing the health of the economy. By using these indices, investors can manage risk, identify investment opportunities, and operate more effectively in financial markets.

Advantages and Disadvantages of Using Stock Market Indices

Stock market indices are tools that enable investors to analyze and evaluate the performance of different market sectors. Advantages include providing an overall market snapshot, simplifying the decision making process, and enabling investment performance evaluation. Additionally, indices serve as benchmarks for comparing the performance of investment funds or portfolios. However, there are limitations. Indices may not offer a complete picture of the market, as they often cover only a portion of listed stocks. Moreover, the heavier weighting of larger companies can create a skewed view of market performance.

The Difference Between Weighted Indices and Price Based Indices

Market cap weighted indices, such as the S&P 500, are calculated based on the market capitalization of companies meaning firms with higher market value have a greater impact on the index. In contrast, price weighted indices like the Dow Jones Industrial Average focus solely on stock prices, without considering the number of shares or total market value. While market cap weighted indices offer a more accurate reflection of the overall market due to their emphasis on company size, price weighted indices are simpler and more suitable for analyzing the price trends of individual stocks.

Relationship Between Stock Indices, Index Funds, and ETFs

Index mutual funds and ETFs use stock indices as models to mirror the performance of a target market. These funds purchase the stocks included in a given index and track their value changes. This approach reduces management costs and allows investors to achieve market like returns at a lower cost. As a result, indices have evolved into tools not only for market analysis but also for investment management guidance.

Stock Indices as Tools for Market Trend Forecasting

Because stock indices reflect changes in stock prices and value, they allow investors to anticipate future market trends. Indices provide a general view of how different sectors of the economy are performing. For instance, a consistent rise in indices like the S&P 500 may indicate economic growth, while a prolonged decline could signal a recession.
Analysts use these indices to identify patterns and turning points in the market. For example, analyzing industry specific indices like Nasdaq for technology or the Dow Jones for large corporations can offer insights into the condition of their respective sectors. However, it’s important to remember that indices are just one tool among many other factors such as economic policy and global conditions must also be considered.

How to Analyze Stock Market Indices

There are several methods for analyzing stock market indices that help investors gain a better understanding of market performance:

• Historical Analysis:

Examining the past trends of indices can reveal recurring patterns and assist in forecasting future behavior.

• Comparative Analysis:

Comparing different indices, such as theS&P 500andNasdaq, can highlight which segments of the market are performing better.

• Using Ratios:

Analyzing financial ratios such as thePrice to Earnings (P/E) ratioorDividend Yieldof companies within the indices can provide valuable insights into stock valuations.

• Correlation Analysis:

Some indices may correlate with macroeconomic variables such as interest rates or oil prices. Studying these relationships can help assess broader market conditions.
Analyzing indices requires accuracy and a deep understanding of the variables influencing the market, as external factors can also impact index movements.

Introduction and Overview of the World’s Most Important Stock Market Indices

Stock market indices serve as benchmarks for evaluating market performance and play a key role in investment decision making and economic analysis. Below is an introduction and overview of the most important stock indices globally:

S&P 500 Index

This index tracks the performance of 500 of the largest U.S. companies across various industries. The S&P 500 is market cap weighted, meaning companies with larger market capitalizations have a greater impact on the index. It is often regarded as a representative of the overall U.S. stock market and a barometer of the country’s economic health. A steady rise in this index may indicate a strong and healthy economy.

Dow Jones Industrial Average (DJIA)

One of the oldest stock indices, the DJIA measures the performance of 30 large and leading U.S. companies. Unlike the S&P 500, it is price weighted, meaning that higher priced stocks exert more influence on the index. Due to its long history and inclusion of "blue chip" companies, the Dow is widely considered a key economic indicator.

Nasdaq Composite

This index includes over 3,000 companies, primarily in the technology and innovation sectors. It was specifically designed to track the performance of tech driven companies. Rapid growth in the Nasdaq often reflects increased innovation and progress in the tech industry. Nasdaq also covers both small and large companies, with a focus on tech driven startups.

Russell 2000 Index

The Russell 2000 tracks the performance of 2,000 small cap companies in the U.S. market. It serves as a benchmark for evaluating the health of the small and mid cap sector. This index provides investors with insights into the performance of less prominent, higher risk segments of the market.

Nikkei 225

The Nikkei 225 is the leading stock index of the Tokyo Stock Exchange, tracking the performance of 225 major Japanese companies. It reflects the economic status of Japan and its top performing corporations. Companies in the Nikkei span a wide range of industries, from technology to manufacturing.

DAX 30 Index

The DAX 30 includes 30 of the largest and most actively traded companies on the Frankfurt Stock Exchange in Germany. This index is seen as a key indicator of the Eurozone economy and covers sectors such as automotive, engineering, and chemicals.

FTSE 100 Index

The FTSE 100 tracks the performance of the 100 largest companies listed on the London Stock Exchange. These companies represent a significant portion of the UK’s market value and the index is widely used to assess the economic climate in the United Kingdom.

Shanghai Composite Index (SSE Composite)

This index represents the overall performance of the Shanghai Stock Exchange, including both domestic and foreign listed companies operating in China. A sharp rise in this index is often viewed as a sign of China’s economic expansion.

MSCI World Index

The MSCI World Index assesses the performance of large and mid cap companies across developed global markets. It serves as a benchmark for international investors looking to gain a comprehensive view of global equity markets in a single index.
These indices are essential tools for analyzing market trends, assessing economic conditions, and managing investments. Choosing the right index for analysis or investment depends on individual goals and target regions. Global indices should be leveraged by investors to diversify portfolios and reduce risk.

How to View Market Indices

To access capital market indices in Iran, start by visiting the official website of the Tehran Securities Exchange Technology Management Company (TSETMC). On this platform, by selecting the "Indicators" section, you can monitor the All Share Index (TEDPIX) as well as real time updates on various industry indices, First and Second Market indices, the Equal Weighted Index, and other specialized indicators complete with price charts and trading volumes.
TSETMC offers built in analytical tools such as trendline drawing, comparison of multiple indices over specific timeframes, and access to historical data, allowing for a comprehensive and in depth market analysis.
In addition to the official website, brokerage platforms and trading apps also provide access to stock market indicators via customizable dashboards. These systems typically include features such as custom filter creation (based on criteria like percentage change, trade value, or volume) and price alert notifications for index movements.
Using these tools, investors can more accurately monitor overall market trends and sector behavior, and develop or refine investment strategies based on real time data, verified insights, and technical analysis.

Global Market Indices and Their Role in International Investing

Global indices such as the MSCI World and FTSE All World allow investors to evaluate the performance of various markets in a unified manner. These indices play a significant role in international investing, as they help investors diversify their portfolios and reduce risks associated with geographic concentration.

• MSCI World Index: This index includes large and mid cap companies from 23 developed markets and serves as a key benchmark for global investors.
• FTSE All World Index: Covering over 3,000 companies from both developed and emerging markets, this index provides a comprehensive view of global markets.
• Dow Jones Global Index: Tracks the performance of global markets, including the U.S., Europe, and Asia, and is a suitable benchmark for international investors.
• S&P Global 100: Consists of large multinational companies with broad exposure to international markets.

These indices enable investors to make informed decisions based on a global perspective and take advantage of economic growth opportunities across different regions.

Introduction to Various Stock Market Indices in Iran

Stock market indices are tools that reflect the overall condition of the capital market and track changes in stock prices and values. In Iran, there are also various indices used to analyze different sectors of the market, the most important of which are introduced below.

Overall Index (TEDPIX)

This index is considered the main benchmark of Iran’s capital market and provides a general picture of market performance. The overall index calculates changes in stock prices along with the dividends paid by companies and serves as a measure of investment returns across the entire market.
The overall index is commonly cited in news as an indicator of the general market condition and is used by investors to assess market trends. It gives more weight to larger companies, as their market capitalization is greater.

Equal Weighted Overall Index

Unlike the overall index, in this index, all companies have equal influence in the calculations. That is, changes in the stock prices of both small and large companies are reflected equally. This feature makes the equal weighted index a more accurate representation of the overall market performance, especially when large companies experience significant fluctuations.

Price Index

This index considers only changes in stock prices and does not account for dividends paid by companies. Therefore, the price index merely reflects general stock price movements and should be used alongside other indices for more precise analysis.

Equal Weighted Price Index

This index is similar to the price index but gives equal weight to all companies, regardless of their size or market value. This characteristic helps in a more detailed analysis of the overall market trend and in identifying the impact of fluctuations in smaller companies.

Free Float Index

This index focuses on the portion of companies’ shares that are available for trading. Free float includes shares that are not intended to be held for company management and can be easily traded in the market. This index is useful for assessing segments of the market with higher liquidity.

Top 50 Most Active Companies Index

This index tracks price changes of the 50 companies with the highest liquidity. The Securities and Exchange Organization updates this list every three months. This index is useful for identifying highly traded company stocks in the market.

Top 30 Largest Companies Index

This index is calculated based on the market value of the 30 largest companies listed on the stock exchange and reflects the price changes of these companies. It is useful for analyzing the status of large companies that have a significant impact on the market.

Industry Index

The Tehran Stock Exchange includes various industries such as petrochemicals, automotive, and basic metals. The industry index measures the price changes of manufacturing companies in these sectors, and each industry has its own specific index, such as the automotive index or the agriculture index.

Financial Index

This index shows the price changes of companies active in the financial sector, such as investment and leasing companies.