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the instruments

Index funds & ETFs

Two vehicles, one philosophy.

Here's how they work, and how to tell if one you're looking at is actually any good.

what are they, really

A fund that just... copies an index

Index funds and ETFs are both passively managed — their entire job is to replicate a rule-based index, in the same proportion as the index itself.

A quick example

Say an index has 3 stocks — weighted 50%, 25% and 25%. Invest ₹100 through an index fund tracking it, and here's exactly where your money goes:

A · ₹50
B · ₹25
C · ₹25
Stock A — 50% weight Stock B — 25% weight Stock C — 25% weight
📈
If the index rises
+15%
your fund broadly rises too
📉
If the index falls
−15%
your fund falls with it

In real life there's a small gap — fund costs and tracking error — but that's the basic deal.

two ways to go passive

Index fund or ETF — what's actually different?

Both track the same kind of index. How you buy them, and what you need to get started, is where they split.

Index fund

buy it like a regular SIP
  • Buy or sell once a day, at that day's closing price
  • No demat account needed
  • Buy directly from the AMC, or any investing app
  • Great for monthly SIPs and beginners
BEST FOR: set-it-and-forget-it investors

ETF

buy it like a stock
  • Trades all day on the stock exchange, live prices
  • Needs a demat + trading account
  • Usually a slightly lower running cost
  • Great if you already trade, or invest in lump sums
BEST FOR: people already on a trading app
BOTH ARE: SEBI-regulated · open-ended · taxed like any mutual fund based on what's inside
before you hit invest

4 things worth 2 minutes of checking

Most people only look at cost. A genuinely good fund is a combination of all four.

1

Cost (TER)

The expense ratio is what the fund charges you every year. Lower TER means more of the market's return actually reaches your account.

2

Size (AUM)

Bigger funds (higher assets under management) are usually run more efficiently and tend to be more stable over time.

3

Tracking error

This shows how closely the fund copies its index day-to-day. Lower tracking error means it's doing its one job well.

4

Tracking difference

This is the actual gap between what the index returned and what the fund gave you. Smaller gap, better fund.

Buying an ETF instead? Also glance at liquidity and trading cost — check the daily trading volume and the bid-ask spread before you buy, so you're not paying extra just to get in or out.

Quick answers to common questions

What is the difference between an index fund and an ETF?

An index fund is bought and sold once a day at closing price, like a regular mutual fund SIP, with no demat account needed. An ETF trades all day on the stock exchange like a stock, and needs a demat and trading account.

Which is cheaper, an index fund or an ETF?

ETFs are usually slightly cheaper, but index funds are simpler for beginners and SIP investors since they don't require a demat account.

What should I check before choosing an index fund?

Four things: the expense ratio (TER), the fund's size (AUM), tracking error, and tracking difference versus the index it follows. See our live fund data table for actual current numbers across Indian index funds and ETFs.

What is tracking error?

It measures how closely a fund's day-to-day movement matches its underlying index. A lower tracking error means the fund is copying the index more faithfully. SEBI requires AMCs to disclose this daily.
Source: SEBI

Can I lose money in an index fund?

Yes — index funds still carry full market risk. If the index falls, the fund falls too. They remove company-specific risk, not market-wide risk — see our breakdown of the two kinds of risk for the full picture.