Index Funds
Passive funds that copy an index at rock-bottom cost, betting that the cheap average beats most active managers after fees.
Why you care
An index fund doesn't try to beat the market — it copies it. It buys every stock in an index like the Nifty 50 in the same proportion, with no manager picking winners. That means almost no research cost, which means a tiny TER. The whole bet is simple: after fees, the cheap average beats most people trying to be clever.
Run the numbers
An index fund charges ~0.2% TER; a typical active equity fund charges ~1.75% (illustrative). That's a 1.55%-a-year head start the index fund gets before anyone picks a single stock. To win, the active manager must beat the index by more than 1.55% every year, just to draw level. Most don't.
Where this goes
An index fund's one job is to copy faithfully, and how well it does that is its tracking error — the quality test for anything passive. The exchange-traded version of the same idea is the ETF. And the entire argument rests on its rock-bottom TER: cost is the edge.
Why you care
An index fund is a passive fund that simply replicates a market index — holding the same stocks in the same weights as, say, the Nifty 50 or the Sensex. It does that instead of employing a manager to pick and choose. Nobody is trying to be clever, so there's little research, little trading, and therefore a very low TER. That low cost is not a detail; it is the product.
The argument for indexing follows straight from the cost stack. Active management is a zero-sum game before fees (for every investor who beats the market, another must lag it), and a negative-sum game after fees (everyone pays costs). So the average actively managed rupee must, by arithmetic, underperform the index by roughly the fees it pays. An index fund escapes most of those fees. Over years, that head start compounds into an edge that most active managers can't overcome. The data in India and globally keeps confirming it: a large majority of active equity funds fail to beat their benchmark over long periods (the SPIVA scorecards track this; verify the current figures). Buying the cheap average isn't giving up on returns; it's refusing to pay a high fee for a bet that usually loses.
Run the numbers
The head start, made concrete (illustrative):
| Index fund | Active equity fund | |
|---|---|---|
| TER | ~0.2% | ~1.75% |
| What it must do to win | just track the index | beat the index by >1.55%/yr |
| Cost drag over 20 years on ₹10 lakh | small | large (see the TER node) |
The active manager isn't just competing with the market; he's competing with the market plus a 1.55%-a-year handicap he handed the index fund by charging more. Some managers clear that bar in some periods. Very few clear it consistently, and you can't reliably know in advance which ones will. That uncertainty, set against the certainty of the cost difference, is why indexing has become the sensible default for the core of most portfolios.
Where this goes
Because an index fund's only job is to copy, the measure that matters for it is tracking error — how far it drifts from the index it's meant to mirror. The same passive idea, wrapped so it trades on the exchange intraday, is the ETF. And underneath all of it sits the TER: the index fund's low expense ratio is the entire source of its edge, which is why, when choosing one, the cheapest faithful tracker usually wins.