On the same Sunday you make two decisions. You start a ₹10,000 monthly SIP into a large index fund, after about ninety minutes of reading and a conversation at home. And you sign a builder’s allotment letter for an under-construction flat, after roughly the same ninety minutes, because the launch price holds only until the thirty-first. One of those decisions can be undone next month at a cost of nothing at all. The other cannot be undone at any price you would accept, for several years, and possibly ever. They received identical deliberation, and that is the mistake — not either decision individually.
A door that swings both ways lets you walk through, look around, and come back if the room is wrong. A door that latches behind you does not. You would step through the first without much thought and stand outside the second for a while, and no one would call that inconsistent — the deliberation is proportionate to the cost of being wrong, not to the size of the room.
Almost every financial decision is one of these two doors, and the door type is rarely printed anywhere on the product. Working it out before you commit is a separate exercise from deciding whether the product is any good, and it is the one people skip.
Reversibility is a price, and it can be computed
Reversibility is not a mood or a feeling about a product. It is a rupee figure plus a period of time, and both halves can be established before you commit — usually in under half an hour, from documents the seller is obliged to give you. The figure has five components, and most households count only the first.
- Transaction costs
- Brokerage, statutory charges, stamp duty, registration, legal and documentation — paid again on the way out, and often paid a third time on whatever you replace it with
- Price impact
- The impact cost of selling your quantity rather than one share of it. Small and invisible in a largecap, several per cent in a thin smallcap, and in an unlisted holding not a cost so much as an absence — there is no market price to sell into, only whatever a private buyer offers
- Penalty or load
- An exit load on fund units redeemed inside the stated period, a premature-withdrawal penalty on a deposit, a surrender charge on a long-dated contract
- Tax crystallised
- A sale converts an unrealised position into a taxable event whose treatment depends on the asset and the holding period. Reversing a decision early can move it into a different treatment entirely — look the current position up rather than carrying a rule of thumb
- What you cannot do while locked in
- A lock-in does not merely delay the exit. It removes the holding from every future decision — it cannot fund an emergency, cannot be rebalanced, and cannot be sold when you change your mind
Example: Two ₹5 lakh commitments. Units in a liquid index fund held past any load: reversal costs a few hundred rupees, whatever tax is due on the gain, and one working day. An under-construction flat: stamp duty and registration already paid and not recoverable, a builder’s cancellation charge under the allotment terms, months on the market, a discount to shift it, brokerage on the way out, and no ability to sell a part of it. Same amount, same Sunday, and the second figure is not in the same order of magnitude as the first.
| Commitment | How long before you can undo it | What the reversal costs |
|---|---|---|
| A listed largecap or an index fund | The next trading session, subject to settlement | Charges, tax on any gain, and negligible impact cost. The closest thing to a two-way door in the market |
| A thin smallcap position | Possibly several sessions to exit a large holding | Charges and tax, plus impact cost that rises with your size. Illiquidity is asymmetric — you choose the day you enter, and the exit is often chosen for you, so the same thin order book costs far more on the way out |
| Fund units inside the load period | Immediately, at a price | The stated exit load on the units redeemed, plus tax. A known, printed number in the scheme document |
| A tax-saving equity scheme | Only after each instalment completes its statutory lock-in | Nothing but time — and time is the cost. No emergency, no rebalance and no change of mind reaches those units |
| A retirement account with a statutory exit age | Not at will. Partial withdrawals and early exit are permitted only on specified conditions | The conditions themselves are the cost, and they are set by regulation rather than by the provider |
| An under-construction property | Months, and only if a buyer appears | Duty and registration already spent, cancellation terms in the allotment letter, brokerage, a price concession, and no ability to sell a portion |
| A long-dated insurance contract | Once it has acquired a surrender value under its own terms, and not before | Costs are front-loaded, so an early exit returns materially less than has been paid in — which is a fact about how the product is built, not by itself a reason to keep paying |
The lock-in that is not in any document
Printed lock-ins are the easy case, because someone has told you about them. The harder ones are structural, and they bind just as tightly. A holding you cannot sell without a family argument is locked in. A flat your parents live in is locked in. If you are a designated person under your employer’s insider-trading code, shares in that employer are untradeable for a substantial part of each quarter, because the window shuts at the quarter end and reopens only a stated interval after the results are declared. A position large enough that selling it would move the price against you is partially locked in, and the size of that lock grows with your own position.
- Concentration creates its own lock-in. A holding that has grown to a quarter of your portfolio has, by growing, become expensive to reduce — the gain is large, so the tax event is large, and every trim is now also a decision about tax. The position has quietly acquired a door that swings only one way.
- Illiquidity is asymmetric. Buying into a thin stock is easy, which is precisely what disguises the problem. Your entry was a small share of the day’s volume; your exit, later and larger, may not be. Check the traded quantity for the size you intend to hold, not for the size you are starting with.
- A joint or family holding needs more than your consent to reverse. Anything held jointly, or bought with money that belongs to a household rather than a person, has a reversal process with other people in it. That is not a reason against it, and it belongs in the estimate.
- Physical assets carry a search cost. Property, unlisted shares and gold in a locker all require you to find a buyer rather than meet one. The wait is part of the reversal cost even when the eventual price is fine.
- Some reversals need somebody else’s consent, and some are not available at all. A guarantee you have signed cannot be discharged by you alone — the lender has to release you. A nomination can be changed at will; a transfer already registered cannot be undone by changing your mind about it. Money given away should be planned for as gone, whatever narrow routes back the law may leave open. Establish which of these you are doing before, not after.
What to do with a one-way door you cannot avoid
Some irreversible decisions are worth making. A house you will live in for twenty years, a retirement account with statutory conditions, a business you are building — none of these becomes wrong because it is hard to undo. What changes is how they should be entered.
- 1Take the decision in instalments where the product allows it
Three tranches across a year converts one irreversible commitment into three smaller ones, of which two are still ahead of you when the first begins to tell you something. This is available far more often than people notice — in fund purchases, in position building, and in staged payments.
- 2Buy the reversible version first, where one exists
Rent in the locality for a year before buying in it. Hold a listed proxy before committing to the unlisted version. Run the strategy at a tenth of the size for two quarters. The information you are buying is what it feels like to hold the thing, which no amount of reading supplies.
- 3Write the exit conditions down while the door is still open
Not a price target — the conditions under which you would want out, in plain words. After the door latches, every reason to leave will be competing with the sunk cost, and a sentence written by the calm version of you is the only counterweight that will be available.
- 4Size it so that being stuck is survivable
The correct question for an irreversible commitment is not what it will earn but what happens if you are wrong and cannot leave for five years. If that scenario breaks the household, the size is wrong regardless of how good the opportunity is.
Transaction costs are only the first of the five components, and they are the one you can actually compute in advance. Run your own typical trade size through it, then remember to add impact cost, any load, and the tax event.
Two commitments, one weekend
You have ₹12 lakh to deploy. Option A is a diversified equity fund, no exit load beyond a short initial period. Option B is a plot on the outskirts of the city, from a developer, at a launch price valid to the end of the month, which a colleague says has "already appreciated" in an earlier phase.
Which of these two commitments deserves more deliberation, and on what grounds? (i) ₹15 lakh into a large index fund. (ii) ₹3 lakh as booking money on an under-construction flat.
Ek hi Sunday: das hazaar ka SIP shuru kiya, aur builder ka allotment letter bhi sign kar diya. Dono pe utna hi socha. Par SIP agle mahine band ho sakta hai, aur flat mahino tak nahi nikalta — stamp duty ja chuki, cancellation charge alag, aur khareedar dhoondhna padega. Isiliye sochne ka waqt paise ke hisaab se mat baanto, wapas aane ki keemat ke hisaab se baanto. Chhota amount jo phans jaata hai, woh bade amount se zyaada sochne layak hai.
- Reversibility is a rupee figure plus a period of time, and both can be established before you commit.
- The five components: transaction costs, impact cost, load or penalty, the tax event crystallised, and what a lock-in prevents you doing.
- Spend deliberation in proportion to the cost of reversing, not in proportion to the amount.
- Structural lock-ins — concentration, illiquidity, joint holdings, family use — bind as tightly as printed ones.
- Where a one-way door is unavoidable, buy optionality back: instalments, a reversible version first, written exit conditions, and a survivable size.
Mark it done to track your progress through the curriculum.
Common questions
Short, direct answers to what people ask about this topic.
- what makes a financial decision hard to reverse
- Five things, and most households count only the first: transaction costs paid again on the way out, the impact cost of selling your quantity rather than one share, any exit load or premature-withdrawal penalty, the tax event a sale crystallises, and everything a lock-in prevents you doing while the money is stuck. Together they give a rupee figure and a period of time, and both halves can usually be established in under half an hour from documents the seller is obliged to give you.
- the extra cost of selling a large quantity of a thinly traded stock is called
- Impact cost — the amount the price moves against you because your own order is a large share of the liquidity available that day. It is negligible in an index fund or a largecap and can run to several per cent in a thin smallcap. Illiquidity is asymmetric: you choose the day you enter, the exit is often chosen for you, so the same thin order book usually costs far more on the way out than it did on the way in.
- can I cancel an insurance policy soon after buying it
- A policy can be returned during the free-look period, which runs from when you receive the policy document, with the premium refunded subject to specified deductions. The period and the mechanics are set by IRDAI regulations rather than by the insurer’s goodwill. Once it has passed, exiting means surrendering the contract, and because costs on long-dated policies are front-loaded an early surrender returns materially less than has been paid in.
- what does it cost to reverse a ₹5 lakh index fund purchase
- A few hundred rupees in charges, whatever tax is due on the gain, and roughly one working day, assuming the units are past any exit load period. Impact cost at that size in a large index fund is effectively nil. The same ₹5 lakh in an under-construction flat is not in the same order of magnitude: stamp duty and registration are already spent, the allotment letter carries cancellation terms, and a buyer takes months and a price concession to find.
- how much time should I spend on a financial decision
- Spend deliberation in proportion to the cost of reversing the decision, not in proportion to the amount of money. A ₹20 lakh index fund purchase can be undone on the next trading day for charges and tax, so it deserves less thought than a ₹4 lakh booking on an under-construction flat that cannot be undone for months. Rupees are the wrong axis — how hard the door is to reopen is the right one.