Understanding BSE 100 – A Detailed Guide

The BSE 100 Index, containing diverse sectors, is a scale for the larger Indian stock market beyond the confines of the well-known BSE Sensex. This guide aims to unravel the nuances of the BSE 100, shedding light on its influence and relevance in shaping investment decisions. 

What is BSE 100?

The BSE 100, also known as the Bombay Stock Exchange 100, is a stock market index in India comprising the top 100 companies listed on the Bombay Stock Exchange (BSE). This index is designed to represent the overall performance of the Indian stock market by including companies from various sectors such as finance, energy, technology, and manufacturing. 

The BSE100 index is calculated using a free-float market capitalisation-weighted methodology, which means that the market value of each company’s shares is adjusted based on the number of shares available for public trading. This allows for a more accurate representation of the market’s performance and the relative importance of each company within the index.

For investors, the BSE 100 holds significant value as it provides a benchmark for evaluating the performance of their investments and the broader market trends. By tracking the BSE 100, investors can gain insights into the overall health of the Indian stock market, make informed decisions regarding their investment strategies and understand the true BSE 100 meaning.

History of BSE 100

The history of the BSE 100 index dates back to its inception in 1989. It was introduced by the Bombay Stock Exchange as a means to provide investors with a comprehensive gauge of the Indian stock market. 

The index started with a base value of 1,000 and has since undergone multiple revisions to ensure its relevance and accuracy. Over the years, the BSE100 index has witnessed various milestones and fluctuations, reflecting the dynamic nature of the Indian economy and the stock market. 

It has weathered economic crises, technological advancements, and regulatory changes, always striving to maintain its position as a reliable benchmark for investors. The BSE 100 index has become an integral part of the Indian financial landscape, serving as a reference point for market analysis, investment decision-making, and overall assessment of the Indian capital market.

How to Invest in BSE 100?

Investing in the BSE 100 index can be a strategic way to participate in the growth of the Indian stock market. 

Step 1: Research and Education

Learn about the BSE 100 index, its components, and how it functions. Familiarise yourself with the sectors and companies represented in the index to assess their growth potential.

Step 2: Select a Brokerage Account

Choose a reputable brokerage firm that offers access to the BSE 100 index. Consider brokerage fees, research tools, customer support, and ease of use when selecting your brokerage account.

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Step 3: Fund Your Account

Deposit funds into your brokerage account to have the necessary capital for investment. Evaluate your risk tolerance and investment goals to determine the appropriate amount to invest in the BSE 100.

Step 4: Develop an Investment Strategy

Consider your investment horizon and risk appetite when developing an investment strategy for the BSE 100. Decide whether you want to invest long-term or engage in short-term trading strategies.

Step 5: Place Your Trade

With your strategy in place, use the trading platform provided by your brokerage to place your trade in the BSE 100 index. Monitor the market closely and execute your trade at the desired price point.

Step 6: Review and Adjust

Regularly monitor and review the performance of your BSE 100 investment. Keep up with market news, economic trends, and company-specific developments to make informed decisions regarding your investment portfolio.

Stocks Selected to be a Part of the BSE 100

BSE 100 includes a diverse range of popular stocks from various sectors. Some prominent stocks within the BSE 100 index include Reliance Industries Ltd., Tata Consultancy Services Ltd., HDFC Bank Ltd., Infosys Ltd., and ICICI Bank Ltd.

  • Reliance Industries Ltd. is a conglomerate with petrochemicals, refining, telecommunications, and retail business interests. 

  • Tata Consultancy Services Ltd. is one of the largest IT services companies globally, providing a wide range of technology solutions and consulting services. 

  • HDFC Bank Ltd. is a leading private sector bank in India, known for its strong financial performance and extensive network of branches. 

  • Infosys Ltd. is a global IT consulting and services leader offering cutting-edge solutions to clients worldwide. 

  • ICICI Bank Ltd. is a trusted name in the banking sector, providing a comprehensive range of financial products and services to individuals and businesses.

Investing in these popular stocks within the BSE 100 index can expose investors to well-established companies with a proven track record of success. That said, conduct thorough research and analysis before making investment decisions to ensure alignment with individual financial goals and risk tolerance.

Steps to Calculate Float-adjusted Market Capitalisation

To calculate the float-adjusted market capitalisation of stocks within the BSE 100 index, follow these steps:

  1. Determine the market capitalisation of each stock

    Market capitalisation is calculated by multiplying the stock’s current market price by the total number of outstanding shares. This information can typically be found on financial websites or your brokerage platform.

  2. Identify the float

    The float refers to the number of shares available for trading in the open market. It excludes shares held by insiders, such as company executives or large institutional shareholders. The float is generally disclosed in a company’s financial reports or can be obtained from reliable sources.

  3. Calculate the float-adjusted market capitalisation

    Multiply the market capitalisation of each stock by the float percentage. The float percentage is calculated by dividing the number of shares available for trading (float) by the total number of outstanding shares. This adjustment accounts for the portion of shares that are actively traded in the market.

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  1. Sum up the float-adjusted market capitalisation of all stocks

    Add the float-adjusted market capitalisations of each stock within the BSE 100 index. This will give you the total float-adjusted market capitalisation for the index.

Criteria for Selecting Stocks

When selecting stocks within the BSE 100 index, consider five important criteria to make informed investment decisions:

  1. Analysing the company’s financial health and stability is crucial. This involves examining the company’s profitability, debt levels, and cash flow.

  2. Understanding the company’s competitive position and industry dynamics can provide insights into its long-term growth potential.

  3. Evaluating the company’s management team and track record is essential to assess their ability to effectively lead the organisation.

  4. Considering the company’s valuation, including price-to-earnings and price-to-sales ratios, can help determine if the stock is priced reasonably.

  5. Keeping an eye on the company’s dividend policy and history can be important for investors seeking income.


The BSE 100 offers investors a diverse and well-balanced portfolio, with exposure to some of the top companies in India across various sectors. Its stable performance and consistent growth make it a popular index among domestic and foreign investors.


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