An ETF and an index fund can both passively track, say, the Nifty 50. The index is the same; the wrapper is different — and the wrapper decides how you buy, what you pay, and how smooth the experience is.
Index fund: a mutual fund that tracks an index
- Bought and sold at end-of-day NAV, directly from the AMC or a platform.
- No demat or trading account needed.
- SIP-friendly — automate a fixed monthly amount easily.
- TER is low, though usually a touch higher than the equivalent ETF.
ETF: an index tracker that trades like a stock
- Listed on the exchange; you buy/sell live during market hours at a market price.
- Requires a demat + trading account.
- TER is often even lower than an index fund.
- But you pay brokerage and cross the bid–ask spread, and the market price can drift from the fund's underlying value (a premium or discount), especially when liquidity is thin.
The catch with ETFs in India
Many Indian ETFs are lightly traded. Low liquidity means wide bid–ask spreads — you might buy a little above fair value and sell a little below it. For a small or regular investor, that hidden cost can quietly wipe out the ETF's lower TER advantage. Liquidity, not the headline expense ratio, is often the deciding factor.
Which should you use?
- Most retail investors doing monthly SIPs → index fund. It's simpler, automatable, needs no demat, and you transact at NAV without spread risk.
- ETFs suit investors who already use a demat account, are deploying lump sums, want intraday flexibility, or need a specific exposure best accessed as an ETF (a gold ETF, for instance, or certain niche indices).
What to check either way
- Tracking difference — how closely the fund follows its index after costs (smaller is better).
- TER — and, for ETFs, the typical spread and trading volume.
- The index itself — make sure you actually want exposure to what it represents.
Both are good, low-cost tools and far better than overpaying for underperformance. The choice is mostly about how you prefer to buy and hold: hands-off and automated points to an index fund; demat-savvy and tactical points to an ETF.