Index Fund vs ETF: One Rule, Two Ways of Delivering It
An index fund and an exchange traded fund can follow one and the same rule and still reach a portfolio by different routes. One is transacted with the scheme at a value struck once for the cycle. The other trades on an exchange all day at a price another holder sets. The rule is identical, so what differs is delivery: how the units are bought, what buying costs, and what can hold them.
Most comparisons of these two open by listing differences. Once the extent of the sameness is clear, the differences stop being a choice about what to hold and become a choice about how to arrive. So the sameness comes first. The working example throughout is the Anantara Multi-Asset Portfolio, an invented discretionary mandate of Rs 500 crore run for an invented charitable endowment, with Rukmini Deshpande chairing its investment committee and Faiz Ahmad Ansari running the mandate.
Two things settled earlier carry into this comparison. A holding that follows a stated ruleA published set of instructions saying what a holding must contain and in what proportions. The holding follows it rather than choosing around it. carries an exposure whose composition is decided by the rule rather than by a person. A percentage without its base has said nothing, so every weight below is stated with the base it was measured against.
Both arrangements follow the identical rule. How much of the exposure does the choice between them change?
What is each of these two, before anything is contrasted?
An index fund is a delivery shape in which the account transacts with the scheme itself. The account places an instruction, the scheme accepts it, and the account receives a holding whose composition is set by the stated rule. There is no counterparty in the ordinary sense: the account is not buying from another holder, it is arriving at the scheme's door.
An exchange traded fund is a delivery shape in which the account transacts on an exchange. The account places an order with a broker, the order meets somebody else's order, and the account receives the same kind of rule-following holding from whoever was on the other side. The scheme is not the counterparty at all. The scheme is what gets traded between holders while the market is open.
The rule decides what the holding contains, and the rule is the same on both sides. Both statements are about the route in and the route out. Set an arrangement that selects its holdings against one that follows a rule and two things change at once. Here one thing changes.
Neither statement says how many units exist, what one is worth, or how one comes into being, all of which is covered separately. Only the outside matters: where the account stands when it transacts, and what it holds when it is done.
How much of the exposure does the choice actually decide?
None of it, and this is the claim the comparison is built on. If two arrangements follow the same rule, the names they hold are the same names and the proportions are the same proportions. The holdings and the proportions are held constant by construction, so nothing that follows in this comparison is about what the account holds.
Most comparisons in portfolio work vary what is contained as well as how it is delivered, and separating those effects is difficult. Holding the rule constant leaves one moving part, so every difference found below is a delivery difference.
Put it in the mandate's own numbers. The Anantara Multi-Asset Portfolio wants a Rs 60 crore exposure to a single stated rule inside its Rs 300 crore equity sleeve. The Rs 60 crore order is 20.0 per cent of the sleeve and 12.0 per cent of the Rs 500 crore portfolio. Both readings are correct and they answer different questions, so both bases are named together. Neither moves if the exposure arrives by one route rather than the other.
Which side of the transaction is the account facing?
On one route the account transacts with the scheme, and on the other the account transacts with another holder on an exchange, and that single fact generates every remaining difference in the comparison.
Transacting with the schemePlacing an instruction directly with the arrangement itself rather than with another holder, so no other holder needs to want the opposite side. means nobody has to want the other side of the trade. On an exchange somebody does, and if nobody does, the order waits or moves the price until one appears.
A street vendor selling cut fruit serves a customer the moment that customer walks up with money, whether or not anybody else on the street wants fruit today. Suppose instead that the only fruit available is fruit someone else already has. On a busy morning a seller turns up in seconds; on a quiet afternoon there may be nobody, or somebody who will part with theirs only at a price the buyer would rather not pay.
The comparison so far describes the shape of the transaction, not which shape is better. Both have a moment where something can go against the account, and what follows traces where each one puts it.
Does the account see its number before or after it commits?
On the scheme route the account makes a commitmentThe moment the account has bound itself to transact and can no longer withdraw the instruction. What matters here is what the account knows at that moment. first and learns the number afterwards. The instruction goes in, the cycleThe stated period at the end of which a scheme strikes one value that every instruction received inside that period transacts at. How the value is arrived at is covered separately. closes, and a value is struck. Transacting with the scheme means committing before knowing the exact value the account will receive.
On the exchange route it runs the other way. Trading on an exchange means seeing a price before committing and accepting the risk that the price on offer sits above or below the value of the underlying holdings per unit.
People often present one of these as the safer arrangement, and that is the mistake worth naming. Each route trades one uncertainty for another rather than removing any uncertainty at all.
Ordering sweets by weight for a wedding, from a shop that will weigh them tomorrow, is the first shape: the commitment is made and the quantity comes to light afterwards. Buying a box off the counter at a marked price is the second: the amount paid is known, and the open question is whether the box was worth it.
Which route makes the account commit before it knows exactly what it will receive?
Which route asks the account for something it may not have?
To transact with a scheme, an account needs an arrangement with that scheme. To trade on an exchange, it needs a link to an exchange and a way to settle the trade. The two requirements are different things to have in place, and an account can have one without the other.
For the invented Rs 500 crore mandate this is a non-event. The Anantara Multi-Asset Portfolio already trades listed securities every week and already settles them, so the requirement is met before the question is asked.
Change the account and the criterion changes character. A household putting Rs 20,000/- aside each month may have one arrangement and not the other, and for that account it is the first filter rather than a detail beside the cost comparison. The criterion does not become false as it travels. The criterion is only separated from the account it was true about. A comparison written for one size of account therefore misleads the other unless it says which account it describes.
A household account of Rs 2,00,000/- and the Rs 500 crore mandate face the same choice. Does the same reasoning apply to both?
Which cost components appear on each route, and which do not?
The entry and exit costEverything the account gives up in the act of arriving at a position and in the act of leaving it, as distinct from anything charged for holding it. of a position is a different quantity from anything charged for holding it, and the two routes assemble it differently.
Arriving on an exchange has three components: the broker's charge for handling the order, the quote gapThe distance between the best price somebody is willing to buy at and the best price somebody is willing to sell at, at a given moment. between the best price on each side at that moment, and market impactThe amount an order itself moves the price against the person placing it, by reaching further along the queue of willing counterparties., whatever the order itself moves the price by.
The scheme route may instead carry adjustments on entry or exit, where any apply, and may cause the scheme itself to trade, with that dealing cost sitting inside the pool. The components are not the same components, and two of them are not even visible in the same place. The two shapes cannot be compared component by component.
No rate for a broker's charge, no quote gap, no entry adjustment, no exit adjustment and no dealing cost for any scheme is available, so the comparison is of shapes rather than of amounts. Supplying any of those would be inventing a market. A reader then ends up with a figure they trust and should not.
Can the whole comparison sit in a single table?
The whole comparison fits in one table, and the rows split into two groups. Rows describing the transaction differ; rows describing the portfolio do not.
| Criterion | Index fund route | Exchange traded route |
|---|---|---|
| What exposure arrives | Set by the stated rule | Set by the same stated rule |
| Who is on the other side | The scheme itself | Another holder |
| When the number is known | After the commitment | Before the commitment |
| What the number can differ from | Nothing, it is the struck value | What the underlying is worth per unit |
| What must be in place | An arrangement with the scheme | An exchange link and settlement |
| Shape of the entry cost | Adjustments, where they apply | Charge, quote gap and impact |
| What a large order runs into | The scheme may have to deal | Finding counterparties on the day |
| What constrains position size | The mandate's own limits | The mandate's own limits |
| What monitoring must check | The gap against the rule | The gap against the rule |
| Who writes the rules for it | Regulation, routed below | Regulation, routed below |
A Rs 60 crore order placed in one go on an exchange. What is the risk being run?
Where does a Rs 60 crore order actually meet resistance?
On the exchange route the order has to find people willing to take the other side. If the trading in those units is thin on the day, the order works its way up the queue of willing sellers and pays progressively worse prices as it goes. Market impact then arrives in practice rather than in theory. Spreading it across several sessions reduces what each session absorbs and adds a different exposure: the price can move while the account is still arriving.
Money arriving at a scheme has to be put to work against the rule, so the same order placed with a scheme may instead cause the scheme itself to deal in the underlying holdings. The dealing has a cost and the cost sits inside the pool. The cost does not appear on the account's contract note. Absence from the note makes the cost invisible rather than free, and invisible is worse.
Which route is cheaper for this order depends on two figures that are not available: how much trading in the units happens on a normal day, and what it costs the scheme itself to deal. Naming what is missing is a finding and guessing at it is not, so both are named and the matter stops there.
Knowing the depthHow much can be bought or sold without the price moving much. Deep trading absorbs a large order quietly and thin trading does not. of the trading would say which route is likely to cost less on one day at one size, and nothing beyond that.
So which route is cheaper for that Rs 60 crore order?
What does the same exposure look like arriving by two routes?
The Rs 60 crore order is a scaled illustration built from the Rs 300 crore equity sleeve for teaching, not a position the invented mandate is recorded as holding.
On that order, a price 0.10 per cent away from the underlying value is Rs 0.06 crore, or Rs 6,00,000/-. At 0.50 per cent away it is Rs 0.30 crore, or Rs 30,00,000/-. Applied to the whole Rs 300 crore sleeve the same two rates give Rs 0.30 crore and Rs 1.50 crore, five times larger because the base is five times larger. The rate did not change between those two pairs and the base did. The change of base is the entire reason both bases are stated every time.
Anchor those amounts against something the mandate already carries. For the stated twelve month period its measured cost of delivery was Rs 9.40 crore: a management fee of 1.25 per cent of assets, being Rs 6.25 crore on Rs 500 crore, and a performance fee of 15 per cent of the return above a 10 per cent hurdle. The stated year returned 14.2 per cent, so the excess over that hurdle was 4.2 points. On Rs 500 crore that excess is Rs 21 crore, and 15 per cent of Rs 21 crore is Rs 3.15 crore. Rs 6.25 crore plus Rs 3.15 crore is Rs 9.40 crore, or 1.88 per cent of Rs 500 crore.
A Rs 0.30 crore price gap on the order is about 3.2 per cent of that Rs 9.40 crore, a Rs 0.06 crore gap about 0.6 per cent, and even Rs 1.50 crore about 16 per cent. The delivery difference under comparison here is small beside the cost of delivery the same portfolio already carried for the stated year.
A price 0.10 per cent away from the underlying value, on the Rs 60 crore order. How much is that?
The Rs 60 crore order reads 20.0 per cent of one thing and 12.0 per cent of another. Of what?
What does neither route change about the portfolio?
Leaving this part out is what lets the comparison feel bigger than it is.
The policy weights hold: equity 60.0 per cent at Rs 300 crore, fixed income 30.0 per cent at Rs 150 crore and cash 10.0 per cent at Rs 50 crore read the same whichever route the equity exposure arrived by. So do the mandate constraints, equity between 50 and 70 per cent of the portfolio and no single holding above 5 per cent of it. Neither limit knows how the position was transacted. So does the benchmark, a composite of 60 per cent a broad equity index and 40 per cent a broad bond index, both deliberately unnamed here. And so does the monitoring duty, the same check either way.
The cost of delivery already recorded holds too. Rs 9.40 crore of fees for the stated twelve month period, being 1.88 per cent of Rs 500 crore, turned a gross excess return of 1.6 percentage points over the benchmark into a net shortfall of 0.28 percentage points. Neither delivery route moves that arithmetic by a rupee.
Every difference above is about how the account arrives at a position that was never in question. The choice is an execution choiceA decision about how to get into or out of a position that has already been decided on. It changes the cost and the timing of arriving, never what the portfolio ends up holding. rather than an investment one, and treating it as an investment one is how a small difference collects a large amount of attention.
How does a two-way choice collect more attention than it deserves?
Because it looks decidable, and the questions around it do not. The appearance of decidability is the whole mechanism, and here is what it costs.
The error that gets made, and what it costs
A reader spends a long evening on this choice, reading four comparisons, weighing the arguments, and settling on one of the two arrangements with some satisfaction. Every one of those comparisons was accurate. The rule both arrangements follow is identical, so not one of those comparisons was about what the account would end up holding. The holdings, the proportions and the exposure were the same at the start of the evening and the same at the end of it.
Meanwhile the questions that would actually have changed the outcome received a fraction of that attention. The allocation is one of them: on the invented mandate, the difference between equity at 60.0 per cent of Rs 500 crore and equity at anything else inside the 50 to 70 per cent band. The constraints the arrangement needs in writing are another. The cost of running the whole thing is a third. On this mandate for the stated twelve month period that cost was Rs 9.40 crore, or 1.88 per cent of assets, enough to turn a gross excess return of 1.6 percentage points over the benchmark into a net shortfall of 0.28 percentage points against it.
The cost is misallocated effort at exactly the moment a reader is most engaged, and it is a common outcome rather than a foolish one. A two-way comparison feels decidable in a way an allocation question does not: there are two options, they can be listed, and a choice can be made and felt. An allocation question has no such shape and gives no such satisfaction. An allocation question therefore loses the competition for attention even though it is worth incomparably more.
Name the check and it stops being difficult. Before spending an hour on any comparison, ask what it decides. If the answer is that both options deliver the identical exposure, then what is being decided is how to arrive, and it deserves the attention arriving deserves. Size the question before answering it.
Set against the mandate's recorded cost of delivery of Rs 9.40 crore for the stated year, how large is a Rs 0.30 crore price gap on the order?
Who inside the mandate actually needs this distinction?
Four roles use this distinction, each of them differently. Use by four roles is a better test of whether a distinction is real than any definition.
Faiz Ahmad Ansari, running the Anantara mandate, uses it when he places the order. Once the committee has settled that a Rs 60 crore rule-following exposure belongs in the Rs 300 crore equity sleeve, his remaining questions are all about arriving: scheme or exchange, one session or several, and what he does not know about either. The last question is where the honest answer lives. The record hands him neither the daily trading in the units nor the scheme's dealing cost.
Rukmini Deshpande, chairing the endowment's investment committee, uses it as an agenda filter. When a paper arrives comparing two arrangements, she asks whether it changes what the portfolio holds or how it arrives. If the exposure is identical either way, the paper is an execution note and belongs with the manager.
An analyst reviewing a manager uses it as a control on a claim. The holdings were the same, so a manager who attributes an outcome to having chosen the better of two arrangements following the same rule cannot be claiming better holdings. Only the claim about arriving more cheaply survives, and that needs the trading conditions on the days the orders were worked, or it is not evidence.
A household investor uses it more quietly. Recognising a choice as an execution choice says how much of a finite evening it should get: not that it does not matter, but that it is bounded and the unbounded questions are elsewhere.
Which of the differences are set in regulation rather than chosen?
Several of them. Some of what differs between the routes is a consequence of how each is regulated rather than a choice anybody made, and confusing the two leads a reader to argue with a rule as though it were a preference.
Where the Indian rules sit on this
When a transaction must be received to fall inside a given cycle, at what value it is struck, what may be charged on arriving or leaving, what must be disclosed and how each arrangement is registered are set in regulation, and the Securities and Exchange Board of India publishes the current text at sebi.gov.in. Every condition, minimum, charge limit, disclosure duty and period changes over time and must be checked against the regulation in force. Where a retirement mandate is the setting, the Pension Fund Regulatory and Development Authority at pfrda.org.in is the authority on the same terms, and the exchanges publish index construction rules at nseindia.com and bseindia.com. A threshold written down from memory does not go stale when it moves. The threshold becomes wrong.
When does the distinction stop mattering?
Under any one of four conditions it stops mattering, and the choice does not change the outcome for the holder. Where one arrangement selects its holdings and the other follows a rule, that is a different comparison, covered separately, and none of these four reaches it.
The first is a fixed amount placed every month. A holder committing the same rupee amount on the same date is not choosing a moment to transact, so the exchange route's ability to price during the session is never used, and the scheme route's single value struck for the cycle costs that holder nothing. The feature that separates the two is switched off by how the holder buys.
The second is a gap against the rule wider than the gap between the costs. Neither arrangement follows its rule perfectly. If each drifts from the rule by more than the two costs differ by, the cheaper route is not reliably the one that ends up closer to the rule, and the cost comparison settles less than it appears to.
The third is a trade small enough that arriving on an exchange costs what it saves. The broker's charge, the quote gap and market impact are paid once on arrival; a difference in what an arrangement charges for holding is paid across the whole period. At a small enough amount, or a short enough period, the once-paid part swallows the recurring one. No rate for any of those is available, so where that point sits is not established.
The fourth is an account with no link to an exchange and no way to settle a trade. Only one route is reachable, so the question is settled before the rest of the comparison arises.
The mandate's own arithmetic shows the size of what is argued over. A Rs 0.30 crore price gap on the Rs 60 crore order is 0.06 per cent of the Rs 500 crore portfolio, against a recorded cost of delivery of 1.88 per cent for the same year. Scaled down to a household putting Rs 20,000/- aside each month, 0.10 per cent is Rs 20/-.
None of these conditions announces when it lapses. The monthly amount grows, a trading arrangement gets opened, the two holdings stop following the rule equally well. The condition expires quietly and the distinction is live again with nothing to say so. Rechecking belongs to the moment the account changes rather than the moment the comparison is read.
A holder places the same rupee amount on the same date every month and never watches a screen. What does the choice between the two routes change for them?
What kind of question is the choice between these two arrangements?
References
| Source | What it settles | Where |
|---|---|---|
| Securities and Exchange Board of India | When a transaction must be received, at what value it is struck, what may be charged on entry or exit, what must be disclosed and how each arrangement is registered. | sebi.gov.in |
| Pension Fund Regulatory and Development Authority | The authority where a retirement mandate is the setting rather than an endowment. | pfrda.org.in |
| The exchanges | Where index construction rules and trading arrangements are published. | nseindia.com and bseindia.com |
The Anantara Multi-Asset Portfolio, the charitable endowment that holds it, Rukmini Deshpande and Faiz Ahmad Ansari are invented.
Educational material. Not advice on any investment, tax, budget or market position.
