Ask ten people whether index funds or active funds are better and you will hear ten strong opinions. The useful question is a smaller one: how much of your money should sit in each, and why. Here is how we think about it with clients.
The two approaches in plain words
An index fund buys the shares in a market index, in the same proportion, and holds them. Nobody picks stocks. If the index has 50 companies, the fund owns those 50. Its job is to match the index, minus a small cost.
An active fund has a fund manager and a research team who choose which shares to buy, how much and when to sell. The aim is to do better than a benchmark index. Sometimes they do, sometimes they do not, and you pay more for the attempt.
Both are regulated mutual funds. Both carry market risk. Neither is safer by default: a mid cap index fund will swing far more than a large cap active fund. The category decides most of the risk, not the style.
Where the real difference shows up: cost
Every mutual fund charges an expense ratio, a yearly percentage taken out of the fund's value. Index funds usually charge a fraction of what active funds in the same category charge, because there is no stock-picking team to pay. The gap looks small on paper. Over 15 years it is not.
A worked example
Take ₹10 lakh invested once and left alone for 15 years. Assume the market, before any costs, gives 12% a year. This is an assumed rate for illustration only. Now assume the index fund costs 0.2% a year and the active fund costs 1.2% a year, and that the active fund exactly matches the market before its costs.
| Fund | Yearly cost | Net yearly rate | Value after 15 years |
|---|---|---|---|
| Index fund | 0.2% | 11.8% | about ₹53.3 lakh |
| Active fund, matching the market | 1.2% | 10.8% | about ₹46.6 lakh |
| Gap | about ₹6.7 lakh |
So an active fund in this example has to beat the market by about 1% every year, after the fund manager's own trading costs, just to end level with the index fund. A ₹10,000 monthly SIP over the same 15 years shows a similar gap: roughly ₹49.5 lakh against ₹45 lakh on the same assumptions. Actual returns can be higher, lower or negative, and costs differ from fund to fund.
That does not make active funds a bad idea. It means each rupee in an active fund should be there for a reason.
Where active management has more room
In large cap shares, the biggest 100 companies are tracked by hundreds of analysts. Information spreads fast, and it is hard for any one manager to find a lasting edge. Many active large cap funds have struggled to beat their index after costs over long periods.
Further down the market, the picture changes. Mid cap and small cap companies get less attention, prices can be less efficient, and a careful team has more chances to add value. These categories also carry more risk and need a longer holding period, ideally 7 years or more. Flexi cap funds, where the manager can move between large, mid and small companies, sit somewhere in between.
A simple way to build the mix: core and satellite
The method we use most is called core and satellite. It is not clever, which is why it holds up.
- Core (roughly 50% to 70% of your equity): low-cost index funds tracking broad large cap indices. This part follows the market and keeps your average cost down.
- Satellite (roughly 30% to 50%): one or two active funds in flexi cap, mid cap or small cap categories, where a manager has more room to add value.
Here is how the split often looks for different people. These are starting points for a conversation, not a recommendation for you.
| Who | Index (core) | Active (satellite) | Why |
|---|---|---|---|
| New investor, first SIP of ₹3,000 to ₹5,000 | 70% | 30% | Fewer decisions, low cost, easy to stick with |
| Mid-career, 10+ years to goal | 50% to 60% | 40% to 50% | Time to ride out swings in mid and small cap |
| Within 5 years of a goal | Mostly large cap index | Small, if any | Lower swings matter more than chasing extra return |
Four checks before you pick any fund
- Tracking error, for index funds. This shows how closely the fund follows its index. Lower is better. Two funds on the same index can differ here.
- Consistency, for active funds. Look at rolling 5-year returns against the benchmark, not last year's number. A fund that beat its index in most 5-year windows is more useful to you than one that had a single great year.
- Overlap. Three large cap funds often own the same 30 companies. Holding more funds does not always spread risk.
- Cost. Compare expense ratios within the same category. A higher cost is fine only if there is a clear reason for it.
Mistakes we see often
- Switching from active to index, or the reverse, right after a bad year. Both styles have stretches where they look worse.
- Owning six or seven funds that do the same job. Two to four funds cover most families well.
- Choosing an index fund on a narrow theme and treating it as low risk because it is passive.
- Never reviewing. An active fund that lags its benchmark for three years in a row needs a conversation.
So which one?
For most people, the answer is both. Index funds give you the market's return at low cost and with less to monitor. Active funds, used in the right categories, give a chance at something more. The mix depends on your time horizon, how much tracking you are willing to do and how you react when a fund lags.
If you already hold funds, start by listing them with their categories and costs. That alone usually shows where the overlap and the extra cost are. Our portfolio review does this for you at no charge. You can also read our pages on index funds, equity funds and mutual funds, or try the numbers on the SIP calculator.
General information, not a recommendation of any scheme. Expense ratio and tax figures change; rules as of 2026, check current rules. Mutual fund investments are subject to market risks, read all scheme related documents carefully. Past performance may or may not be sustained in future.
