ETF vs Index Fund: What Is the Real Difference?

If you are starting to invest, you will soon come across two products that sound almost identical: ETFs and index funds. Both track a market index such as the Nifty 50 or the Sensex. Both are usually low-cost. Both suit long-term investing.

So what actually separates them? Mostly the way you buy, sell and pay for them. This guide explains each one in plain English, compares them side by side, and shows why the choice matters less than investing steadily.

What is an ETF?

ETF stands for exchange-traded fund. It is a fund that holds a basket of securities, such as shares or bonds, and its units are listed on a stock exchange. Most ETFs in India track an index, for example the Nifty 50 or the Sensex.

How an ETF works

When you buy one unit of a Nifty 50 ETF, you own a small slice of a fund that holds all 50 companies in the index, in roughly the same proportions as the index. The Nifty 50 is made up of 50 large companies listed on the NSE, weighted by free-float market capitalisation (the value of shares available for public trading). It is not a list of “the 50 best companies”, just 50 of the largest. Instead of buying 50 separate shares, you buy one ETF unit that holds them all.

How you buy and sell an ETF

ETFs trade on the exchange just like shares. This means:

• You need a demat account (where your units are held electronically) and a trading account with a SEBI-registered stockbroker.
• You can buy or sell during market hours.
• The price moves through the day with buying and selling.
• You may pay brokerage and other trading charges, and you face a bid-ask spread: the small gap between the price buyers are offering and the price sellers are asking.

Example: say a Nifty 50 ETF unit trades at ₹200. With ₹10,000 you could buy 50 units, before charges. If the Nifty 50 rises, the value of your units should rise by roughly the same percentage.

What is an index fund?

An index fund is a mutual fund that aims to copy the performance of a market index. Like an ETF, a Nifty 50 index fund holds the 50 Nifty companies in the same proportions as the index.

How an index fund works

Your money is pooled with that of other investors, and the fund house invests it in the companies in the index, following each company’s weight. It does not split the money equally across all 50 companies.

How you buy and sell an index fund

• You buy directly from the fund house or through a mutual fund platform, not on the stock exchange.
• You do not need a demat account.
• Units are bought and sold at the day’s NAV (net asset value, the value of one unit), which is worked out once a day after the market closes.
• SIPs (systematic investment plans, where a fixed amount is invested every month) are easy to set up, often from a few hundred rupees a month, though minimums vary by scheme.
• Direct plans have no distributor commission, so their expense ratio is lower than that of regular plans of the same fund.

Example: if you invest ₹10,000 in a Nifty 50 index fund when the NAV is ₹150, you get about 66.67 units (₹10,000 ÷ ₹150). Mutual funds allot fractional units, so the whole amount is invested. The value of your units changes once a day, when the new NAV is published.

ETF vs index fund: side-by-side comparison

Both follow an index and aim to deliver the index’s return, minus costs. The structure is what differs.

The costs, in detail

Cost is one of the few things you control, so it is worth understanding all of it, not just one number.

Expense ratio

Both ETFs and index funds charge an expense ratio: a yearly fee, taken out of the fund’s value, that covers running costs. You never pay it as a separate bill; it simply reduces your returns.

Example: if you have ₹1,00,000 invested and the expense ratio is 0.20%, you pay about ₹200 a year indirectly.

ETFs often have low expense ratios. Direct plans of index funds can be just as competitive. Regular plans cost more because they include a distributor’s commission.

Brokerage and trading charges

Each time you buy or sell an ETF, you may pay brokerage plus other charges such as securities transaction tax, exchange fees, stamp duty, GST and a depository charge when you sell. You also need to keep a demat account, which may have an annual maintenance charge. Charges differ by broker and change over time.

Index funds have no brokerage. For someone investing a small amount every month, this can make a real difference. So compare the total cost, not just the expense ratio.

Tracking error

No fund copies its index perfectly. Costs, cash held for redemptions and timing all create small gaps. The difference between the fund’s return and the index’s return is called tracking error (or tracking difference). It applies to both ETFs and index funds, and a smaller gap is better. With an ETF there is one more gap to watch: the market price you pay can sit slightly above or below the value of the fund’s holdings, especially if the ETF does not trade much.

Liquidity and flexibility

Liquidity means how easily you can turn an investment into cash.

ETF liquidity

You can sell an ETF any time during market hours at the current price, as long as there are buyers. In ETFs with heavy trading, this is easy. In thinly traded ETFs, the bid-ask spread can be wider and the price may stray further from the fund’s real value. Checking trading volumes before you buy is a sensible habit. ETFs also let you use limit orders, where you set the price you are willing to pay or accept.

Index fund liquidity

You can redeem index fund units on any business day. You get that day’s NAV, and the money usually reaches your bank account within a few working days.

For long-term investors, this short wait rarely matters. Intraday trading is not something a long-term investor normally needs.

Tax on gains

Gains from both ETFs and index funds are taxed. The tax depends on the type of fund (for example, whether it tracks an equity index) and how long you hold it. An ETF and an index fund tracking the same equity index are generally treated alike. FinanceOpen’s tax guides explain the current rules in detail.

Which is better for beginners?

It depends on what you are comfortable with.

An ETF may suit you if:

• You already have a demat and trading account and know how to place orders.
• You want to buy or sell at a known price during market hours.
• You invest larger amounts less often, so brokerage is a small share of each purchase.

An index fund may suit you if:

• You are investing for the first time.
• You want an automatic monthly SIP.
• You prefer not to deal with trading screens, spreads or brokerage.

Many first-time investors find index funds simpler. ETFs work just as well for people comfortable with a trading account. If you are still deciding how to invest each month, our guide on SIP vs lump sum may help, and stocks vs ETFs explains how ETFs compare with buying shares directly.

Example: two investors, same index

Investor A puts ₹10,000 a month into a Nifty 50 ETF. Investor B puts ₹10,000 a month into a Nifty 50 index fund. Both invest for 20 years, a total of ₹24,00,000 each.

Assume both earn 11% a year and invest at the start of each month. This rate is purely an illustration, not a forecast; real returns will be different and will vary from year to year.

• At 11% a year, each would end with about ₹81.6 lakh.
• If one of them lost an extra 0.1% a year to costs (earning 10.9% instead), they would end with about ₹80.6 lakh, roughly ₹1 lakh less.

The lesson: since both track the same index, the end result is very similar. Small cost differences add up over 20 years, but the bigger factors are how much you invest and how long you stay invested.

The bottom line

ETFs and index funds do the same basic job: they give you low-cost exposure to a whole index. ETFs trade like shares and need a demat account; index funds are bought at NAV and make SIPs easy. Pick the one that fits how you like to invest, compare total costs, and then focus on investing regularly for the long term. For personal advice, a SEBI-registered investment adviser can help.