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Beginner/Understanding Mutual Funds/Lesson 8 of 60

Index Funds

A low-cost fund that simply copies a market index like the Nifty 50 instead of trying to beat it.

Why it matters

There are two ways to run a fund. An active fund employs a manager and a research team who try to beat the market by picking the best stocks and timing their trades. An index fund does the opposite. It gives up trying to win and simply copies a market index, such as the Nifty 50 or the Sensex, by holding the same stocks in the same proportions.

Because an index fund needs no star manager and does almost no trading, it costs a fraction of what an active fund charges. That tiny cost difference, repeated every year for decades, is the heart of why index funds have become the sensible default for most long-term investors.

An everyday way to picture it

Imagine the market is a basket holding every major fruit in proportion to its size. An active manager charges you a premium to hand-pick the fruit they expect to ripen best, and sometimes they are right. An index fund just buys one of every fruit in the same proportion as the basket, for a tiny handling fee.

Over a few years, the hand-picker might do better or worse. Over many years, the steady drag of the higher fee tends to leave the cheap basket ahead. That is what the long-run evidence keeps showing.

Active versus passive, side by side

FeatureActive fundIndex fund (passive)
GoalTry to beat the indexMatch the index
Run byA manager picking stocksRules that copy the index
Typical expense ratioAround 1.0% to 2.0%Around 0.1% to 0.3%
Main riskThe manager underperformsYou get the market return, no more
Best suited toInvestors seeking an edge and willing to pay for itInvestors who want the market return at low cost

The catch is that beating the index is hard. The SPIVA studies, which track this in India and worldwide, find that a large majority of active funds fail to beat their benchmark over a ten-year horizon, and cost is one of the biggest reasons why.

See it for yourself

Assume an active fund matches the index before fees, which is roughly the average case. The only difference left is cost. Both start with ₹1,00,000.

Market (index) return per year11%
Active fund expense ratio1.50%
Index fund is held fixed at 0.2%
Years invested20
Index fund value
₹7,77,670
Active fund value
₹6,14,161
Lost to the higher fee
₹1,63,509
The gap is pure cost. Both funds earned the same before fees, yet the cheaper one keeps more of your money working for you, year after year.

Worked example: a 1.3% gap over 20 years

Two investors each put ₹1,00,000 into funds tracking the same market, which returns 11% a year before costs. One pays 0.2% for an index fund, the other pays 1.5% for an active fund that just matches the index before fees.

FundNet return after feeValue after 20 years
Index fund10.8%₹7,77,670
Active fund9.5%₹6,14,161

A fee gap that looks trivial on paper, just 1.3% a year, quietly grows into a large sum over two decades. This is why the cheapest fund that does the job is usually the smart default.

Remember this

IdeaWhat it means
Index fundA fund that copies an index like the Nifty 50 instead of picking stocks
PassiveNo manager trying to win; you simply get the market return
Why it winsVery low cost, and most active funds fail to beat the index long term
The trade-offYou will never beat the market, but you rarely fall far behind it

In short: an index fund buys the whole market cheaply and lets low cost do the heavy lifting. For most people investing for the long run, it is the sensible starting point.