The Pros and Cons of Index Investing

Index funds can offer a relatively simple way to participate in the market without selecting individual stocks. However, simple does not mean risk-free. The index a fund tracks, the costs it charges and how closely it follows its benchmark can all affect investment outcomes.

This article explains how index funds work, their pros and cons, what to compare before choosing one and the steps involved in getting started.

What are index funds?

An investment index, also called a market index, tracks the performance of a selected group of securities. The Nifty 50 and S&P BSE Sensex, for example, track baskets of large companies listed in India.

Index investing is a form of passive investing. Instead of relying on a fund manager to select stocks in an attempt to outperform the market, it seeks to follow the performance of a chosen index.

An index mutual fund invests in the securities that make up its benchmark index, generally in similar proportions. The fund manager adjusts the portfolio when the index changes and manages inflows, redemptions and other operational requirements. The aim is to deliver returns that closely match the index, subject to tracking error, rather than outperform it.

Exchange Traded Funds, or ETFs, follow a similar passive approach but are bought and sold on a stock exchange. In other words, an index fund is itself a type of mutual fund. The key distinction is between passive funds, which track an index, and active funds, where the fund manager selects securities.

Pros and cons of index investing

Like any investment option, index funds come with advantages and limitations. Understanding both can help investors assess whether an index fund aligns with their financial goals, risk tolerance and investment horizon:

Benefits

• Diversification through one investment: A broad market index fund can provide exposure to several companies and sectors through a single investment.
• Relatively lower costs: Passively managed index funds generally have lower expense ratios than actively managed funds.
• Straightforward approach: The fund follows a stated index, making it easier to understand what the portfolio is designed to track.
• Less reliance on stock-picking decisions: Scheme performance does not depend on a fund manager selecting securities with the aim of outperforming the benchmark.
• Flexible investment routes: Index mutual funds generally allow both lumpsum and SIP investments.

Limitations and risks

• Market risk: If the underlying index falls, the fund’s NAV can also decline and investors may lose money.
• No attempt to outperform: The fund aims to match its benchmark, subject to tracking error, rather than outperform it.
• Tracking gaps: Expenses, transaction costs and portfolio adjustments can cause the fund’s returns to differ from those of the index.
• Diversification can vary: Sectoral, thematic or narrowly constructed indices may have significant exposure to a few companies or sectors.
• Limited portfolio flexibility: The fund generally continues to hold index constituents in their assigned weights, even during periods of weak performance.

Overview of major Indian stock market indices

• Nifty 50: The Nifty 50 is a benchmark index that represents the performance of 50 of the largest and most liquid companies listed on the National Stock Exchange. It covers a wide range of sectors and is widely used as a benchmark for investment performance.
• S&P BSE Sensex: The Sensex is a benchmark index that represents the performance of 30 of the largest and most liquid companies listed on the Bombay Stock Exchange. It is widely followed by investors and financial media as a gauge of the Indian stock market’s performance.
• Nifty Next 50: The Nifty Next 50 is an index that represents the performance of the next 50 largest and most liquid companies listed on NSE, after the Nifty 50. It provides a broader representation of the Indian stock market and can be a useful tool for investors looking to diversify their portfolio beyond the large-cap space.
• Nifty Bank: The Nifty Bank index tracks the performance of the banking sector in India. It includes the largest and most liquid banking stocks listed on the NSE .
• BSE Midcap: This represents the performance of the mid-sized companies listed on the BSE.
• Nifty Smallcap: The NSE Smallcap indices represent the performance of the small companies (by market capitalisation) listed on the NSE.

Who should invest in index funds?

Index funds may be considered by investors who:

• Want exposure to a market index without selecting individual stocks
• Prefer a relatively simple and passive investment approach
• Have a longer investment horizon and can tolerate market fluctuations
• Want to invest regularly through an SIP
• Prefer funds whose portfolios follow a clearly defined benchmark
• Are conscious of investment costs

However, index funds may not be suitable for someone seeking assured returns, capital protection or access to money over a short period. The underlying index also matters. A broad-market index and a sectoral or thematic index can have very different levels of concentration and risk.

How to choose an index fund

Two index funds may appear similar but can differ in their underlying index, costs and ability to track the benchmark. The following factors can help investors make a more relevant comparison:

• Understand the underlying index: Check which securities the index includes, the sectors or market cap segments it covers and how weights are assigned. This helps you understand where your money will be invested.
• Assess the risk and investment horizon: Make sure the index aligns with your financial goal and ability to handle volatility. A broad-market index fund and a sectoral index fund, for example, may carry very different risks.
• Compare tracking quality: Review the fund’s tracking error and tracking difference over comparable periods. These measures show how closely the fund has followed its benchmark.
• Check the expense ratio: Compare expense ratios among funds tracking the same index and within the same type of plan. A lower cost can help reduce the gap between the fund and its benchmark, but it should not be the only consideration.
• Choose the investment format: An index mutual fund can generally be purchased through an AMC, distributor or mutual fund platform without a demat account. An ETF is traded on a stock exchange and requires demat and trading accounts. ETF investors should also consider trading liquidity and the difference between quoted buying and selling prices.

What is the expense ratio in an index fund?

The expense ratio is the annual cost of operating a mutual fund scheme, expressed as a percentage of its average daily net assets. These expenses are reflected in the scheme’s NAV rather than being charged to the investor as a separate bill.

Because an index fund seeks to follow a benchmark, its expenses can contribute to the difference between the fund’s return and the index return. A lower expense ratio can therefore be useful, particularly over longer periods.

However, the fund with the lowest expense ratio may not always track the index most efficiently. Investors should consider both costs and tracking quality. Comparisons should also be made on a like-for-like basis, such as direct plan with direct plan or regular plan with regular plan.

What is tracking error in an index fund?

An index fund’s return may not exactly match its benchmark even when it holds largely the same securities. Expenses, transaction costs, cash holdings, corporate actions and the timing of portfolio adjustments can create differences.

Tracking difference is the gap between the returns of a fund and its benchmark over a given period. Tracking error indicates how consistently that gap has varied over time. A lower tracking error generally suggests that the fund has followed its benchmark more consistently.

However, tracking error should not be viewed in isolation. A fund can consistently lag its benchmark because of costs and still report a relatively low tracking error. It is therefore useful to review both tracking error and tracking difference when comparing funds that follow the same index.

Common mistakes to avoid when investing in index funds

Index investing may appear straightforward, but a few common mistakes can affect portfolio suitability:

• Choosing based only on recent returns: Recent performance may reflect market conditions rather than the fund’s tracking efficiency or long-term suitability.
• Assuming passive means risk-free: Index funds reduce dependence on active stock selection but remain exposed to market risk.
• Ignoring the underlying index: Not every index provides broad diversification. Some may be concentrated in a particular sector, theme or group of companies.
• Focusing only on the expense ratio: A low-cost fund may still have a relatively high tracking difference or tracking error.
• Investing in several overlapping funds: Multiple index funds may hold many of the same stocks, adding duplication without providing meaningful diversification.
• Using money required in the short term: Equity-oriented index funds can experience sharp fluctuations and may not be suitable for near-term financial needs.

Steps to start investing in index funds

Here are the steps involved in starting an index fund investment:

1. Understand index funds: Learn about the different indices and the funds that track them. Pay attention to the companies, sectors and market segments represented by each index.
2. Set your investment goals: Consider your financial objective, risk tolerance and investment horizon. Equity-oriented index funds are generally used for longer-term goals because their value can fluctuate significantly over shorter periods.
3. Choose a suitable index fund: Compare funds based on the underlying index, risk level, expense ratio, tracking difference and tracking error.
4. Complete the KYC requirements: Investors generally need to complete the applicable Know Your Customer requirements and provide details such as their PAN, bank account and contact information.
5. Choose between an SIP and a lumpsum: An SIP allows you to invest a fixed amount regularly, while a lumpsum involves investing a larger amount at one time. The minimum investment amount varies across schemes. A SIP mutual fund calculator can illustrate how regular investments may build at an assumed rate of return, although actual returns may vary.
6. Make the investment: You can invest in an index mutual fund through the asset management company, a mutual fund distributor or an eligible investment platform. A demat account is generally optional for an index mutual fund but is required for an ETF.
7. Review the investment periodically: Check whether the fund continues to align with your goal and review its costs, tracking quality and underlying index. Frequent changes based only on short-term market movements may not be necessary.

Conclusion

Index funds can help build a diversified investment portfolio. Their key feature is the potential to deliver market-linked returns at comparatively lower cost than actively managed funds. This cost advantage can contribute to long-term potential returns. It’s also important to recognise their limitations. Since index funds aim to match the performance of a benchmark index (subject to tracking error), they are unlikely to outperform it. They are also exposed to systematic risks that affect the entire market. As a result, any broad market decline may impact the fund’s performance. Index funds may be suitable for investors who want the potential for long-term growth and prefer a comparatively cost-effective and passive investment route.

FAQs

Which is the best index fund for beginners?

There is no single best index fund for every beginner. A broad-market index fund tracking an index such as the Nifty 50 or Sensex may be easier to understand than a sectoral or thematic fund. However, investors should still compare the underlying index, risk level, expense ratio and tracking record.

Can I invest through SIP in index funds?

Yes, most open-ended index mutual funds allow investments through an SIP. You can choose an amount and frequency based on the scheme’s available options. An SIP can support regular investing, but it does not guarantee returns or protect against market losses. ETFs are usually purchased through a stock exchange instead.

Are index funds completely risk-free?

No. Index funds are market-linked and can fall in value when their underlying index declines. They may also face concentration risk, tracking error and liquidity-related risks, depending on the index and investment format. Diversification can reduce company-specific risk, but it cannot remove overall market risk.

How are index funds taxed in India?

Tax treatment depends on the assets held by the index fund. For equity-oriented index funds, gains on units held for 12 months or less are generally taxed at 20%. After 12 months, aggregate eligible long-term capital gains above ₹1.25 lakh in a financial year are taxed at 12.5%. Applicable surcharge and cess may also apply. Debt, gold and overseas index funds may follow different tax rules.

Can I lose money in index funds?

Yes. If the underlying index declines, the NAV of the index fund can also fall. An investor may incur a loss if units are redeemed at a value below their purchase cost. Even broad-market index funds can experience significant declines, particularly over shorter periods.

What is tracking error in index funds?

Tracking error shows how consistently an index fund’s returns stay close to its benchmark. A lower tracking error generally indicates more consistent tracking. However, investors should also examine tracking difference, which shows the actual gap between the fund’s return and the benchmark return.

How often should I review my index fund investments?

There is no mandatory review frequency but reviewing an index fund once or twice a year may generally be sufficient. Check whether it still aligns with your goal, risk appetite and investment horizon, along with any material changes in its expense ratio, tracking quality or underlying index.

Can I invest in multiple index funds?

Yes, you can invest in multiple index funds. However, check their underlying holdings before investing because different indices may contain many of the same companies. Choosing funds with substantially overlapping portfolios can add complexity without meaningfully improving diversification.