Investing
Index Funds
How index funds work, why costs decide long-run returns, and how to pick one in both the Indian and US markets.
An index fund does not try to beat the market — it tries to be the market, holding every stock in an index in the same proportion. That sounds unambitious, and it is precisely why it works: most actively managed funds fail to beat their benchmark over long periods, and the ones that do are hard to identify in advance. What you can control is cost, and index funds are the cheapest way to own a broad market.
Why Low Cost Compounds
The expense ratio looks trivially small on a single year. Over an investing lifetime it is one of the largest determinants of your final corpus.
- A typical Indian index fund charges 0.10–0.20%; an active equity fund often charges 1.5–2.0%
- On ₹10 lakh growing at 12% for 25 years, a 1.5% fee difference costs several lakhs in forgone corpus
- Fees are certain and are deducted whether the fund performs well or badly; outperformance is not certain
- US investors have it cheaper still — broad-market ETFs commonly charge 0.03–0.10%
Choosing an Index Fund in India
Once you have settled on an index, the funds tracking it are near-commodities. Compare on cost and tracking quality, not on past returns.
- Nifty 50: the 50 largest NSE-listed companies — the standard core holding
- Nifty Next 50: the following 50, more volatile with historically higher returns
- Nifty 500: the broadest single-fund exposure to the Indian market
- Compare tracking error — how closely the fund follows its index — alongside the expense ratio
- Prefer direct plans over regular plans; the commission built into regular plans is pure drag
Index Investing in the US Market
The US market offers the deepest and cheapest index products in the world, and Indian residents can access them through several routes.
- S&P 500 trackers give exposure to 500 large US companies (VOO, IVV, SPY)
- Total-market funds (VTI) add mid- and small-caps for broader coverage
- Indian residents can invest via the LRS route, an international feeder fund, or an India-listed global ETF
- Currency matters: rupee depreciation against the dollar has historically added to returns for Indian investors
- Check the tax treatment before committing — US-listed holdings carry estate-tax and reporting considerations
💡 Pro Tip: When two funds track the same index, they are nearly identical products. Pick on expense ratio and tracking error — past return differences between them are noise, not skill.
Key Takeaways
- ✓Index funds track a market rather than trying to beat it, and most active funds fail to beat theirs long-term
- ✓Expense ratio is the single most controllable factor in long-run returns
- ✓Always choose direct plans — regular plans embed a commission that compounds against you
- ✓Nifty 50 is the common Indian starting point; the S&P 500 is the US equivalent
- ✓Tracking error matters as much as headline cost when comparing funds on the same index
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