📊 STOCKS · DIRECT ANSWER
Index Fund vs ETF: Which Actually Costs You Less?
THE DIRECT ANSWER
ETFs usually carry lower expense ratios, but the gap is smaller than the marketing suggests. On ₹10,000 a month for 20 years at 12% gross, an ETF at 0.05% grows to about ₹99,24,031 against ₹97,24,759 for an index fund at 0.20%: a difference of ₹1,99,273, about 2%. For most people the deciding factor is not cost but how you invest: index funds allow automated SIPs and fractional amounts, ETFs require a demat account and trade at market prices that can drift from NAV.
What is the actual cost difference?
| ₹10,000/month · 20 years · 12% gross | Expense ratio | Final value |
|---|---|---|
| ETF | 0.05% | ₹99,24,031 |
| Index fund | 0.20% | ₹97,24,759 |
| Active fund | 1.00% | ₹87,35,731 |
Two things stand out. The ETF-versus-index-fund gap is ₹1,99,273: real, but around 2% of the corpus. The gap between either passive option and a 1% active fund is ₹11,88,300, roughly six times larger. The expensive decision is passive versus active, not ETF versus index fund.
What is the difference in practice?
| Index fund | ETF | |
|---|---|---|
| How you buy | Directly from the AMC | On the exchange, like a share |
| Demat account | Not required | Required |
| Automated SIP | Yes, straightforward | Limited; some brokers offer it |
| Price you pay | End-of-day NAV | Live market price |
| Fractional amounts | Yes: ₹10,000 exactly | Whole units only |
| Expense ratio | Slightly higher | Slightly lower |
| Extra costs | Exit load if applicable | Brokerage, demat AMC, bid-ask spread |
💡 THE KEY INSIGHT
An index fund charges slightly more and asks nothing of you. An ETF charges slightly less and asks you to place a trade every month. If that trade is the thing that stops you investing in month seven, the cheaper product produced the worse outcome.
The hidden cost in ETFs
The expense ratio is not the whole cost. Three things can quietly erode the ETF advantage:
- Bid-ask spread. You buy at the ask and sell at the bid. On a thinly traded ETF that spread can exceed a year's expense-ratio saving in a single transaction.
- Premium or discount to NAV. An ETF's market price can drift from the value of its holdings, particularly during volatile sessions or in low-volume funds. You may pay more than the units are worth.
- Brokerage and demat charges. Twelve purchases a year means twelve transactions, plus annual maintenance on the demat account.
These matter most for exactly the investor an ETF is usually pitched to: someone making small monthly purchases. Check average daily traded volume before choosing an ETF: liquidity is the feature that makes the low expense ratio real.
Which should you choose?
Index fund suits you if
- You invest a fixed amount monthly and want it automated
- You do not have or want a demat account
- You would rather not think about market prices at all
ETF suits you if
- You invest lump sums rather than small monthly amounts
- You already trade and have a demat account
- You are choosing a large, liquid ETF with tight spreads
Assumptions
₹10,000 monthly, 20 years, 12% p.a. gross return compounded monthly with beginning-of-month instalments. Expense ratio deducted from the gross return. Excludes brokerage, demat AMC, bid-ask spread, exit load, tracking difference and taxes: several of which work against the ETF. Expense ratios are illustrative; check current scheme documents. Returns are assumed constant, which real markets are not.
The one-line summary
ETFs are marginally cheaper on paper; index funds are markedly easier to keep doing. Over 20 years the cost gap is about ₹2 lakh, while choosing passive over a 1% active fund is worth about ₹12 lakh. Get the big decision right first.
Frequently asked questions
ETFs usually have lower expense ratios, but the practical gap is small. On ₹10,000 a month for 20 years at 12% gross, a 0.05% ETF reaches about ₹99,24,031 against ₹97,24,759 for a 0.20% index fund: about ₹1,99,273. Index funds are easier to automate and need no demat account, which matters more for most monthly investors.
No. Index funds are bought directly from the asset management company or through a platform, and units are held in a folio. ETFs are traded on the exchange and do require a demat account.
Some brokers offer scheduled ETF purchases, but it is less seamless than a mutual fund SIP. ETFs trade in whole units, so a fixed rupee amount rarely buys an exact number of units, leaving a residual each month.
Tracking error measures how much a passive fund's returns deviate from its benchmark index, caused by expenses, cash holdings and rebalancing timing. Lower is better, and it is worth comparing alongside the expense ratio rather than looking at cost alone.
Compare the impact: SIP calculator
Figures are illustrative at the stated assumptions, not projections. Mutual fund investments are subject to market risks; read all scheme-related documents carefully. Educational content only, not personalised investment advice.