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073You pay Rs 100 to roll a fair die and receive Rs 30 times the face. Should you play? Now suppose that after seeing the roll you may pay Rs 20 to roll once more and take the second result instead. What is your rule, and what is the game worth?Consulting-style caseTreasury
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With the Rs 20 re-roll available, which rolls do you re-roll?
Show the worked solution
Play: one roll pays 30 x 3.5 = Rs 105 on average against a Rs 100 fee, an edge of Rs 5. With the re-roll, keep a 3 or better and re-roll a 1 or 2; the game is worth Rs 118.33, an edge of Rs 18.33. A fresh roll is worth 105 less the Rs 20 fee, 85, so re-roll only a result paying less than 85: 30 and 60 qualify, 90 does not.
Why is the first game worth playing?
A fair die averages 3.5, so the average payout is 30 x 3.5 = Rs 105, more than the Rs 100 you pay. On expected value the game pays Rs 5 a play, so a player who can repeat it should play. Half the time you lose money, since a 1, 2 or 3 pays 30, 60 or 90, and the other half you win 120, 150 or 180; the wins are larger than the losses, which is where the edge sits.
How does the re-roll change the rule?
Think of returning a shirt. You keep it if what you have is worth more than what the shop will hand you after the restocking fee. Re-roll only when the roll in hand is worth less than a fresh roll net of its fee, which is 105 - 20 = Rs 85. A 1 pays 30 and a 2 pays 60, both below 85: re-roll. A 3 pays 90, above 85: keep it, even though 3 is below the average face. The fee is what makes a 3 worth keeping.
Faces 3 to 6 are kept for 90, 120, 150 and 180, while faces 1 and 2 lead to a Rs 20 re-roll worth 85 net, so the game is worth 118.33 against 105 without the option, an edge of 18.33 over the Rs 100 fee. The relationship90 to 180 the payouts kept on a 3, 4, 5 or 6 105 - 20 a fresh roll's average payout less the re-roll fee 2/6 the chance of a 1 or a 2, the rolls you re-roll What it says in wordsThe game is worth the chance of keeping times the average kept, plus the chance of re-rolling times the fresh roll's value after the fee.What does the option itself cost and earn?
The re-roll lifts the game from 105 to 118.33, so the option is worth Rs 13.33 on average, and it also cuts the chance of losing money from a half to a third, because a bad first roll gets a second chance. Re-rolling a 3 as well would give 117.50, worse by 0.83; a free re-roll would make re-rolling the 3 right and lift the game to 127.5. The threshold moves with the fee: below a fee of Rs 15 the 3 is worth re-rolling, above it the 3 is kept. The limit to say: the worst path, a 1 or 2 followed by a 1, costs Rs 90, and a player who cannot afford that should not value the game by its average.
Where candidates lose it
The common loss is re-rolling anything below the 3.5 average, including a 3. The bar is not the average face; it is the value of a fresh roll after its fee, and the Rs 20 fee pulls that bar below 90. Re-rolling a 3 gives up almost a rupee a play.
The quieter slip is forgetting to charge the fee at all, which puts the game at 127.5 and the threshold at 3. State the net value of a re-roll, 85, before deciding anything.
What the interviewer asks next
- The re-roll fee is Rs 10. Which rolls do you now re-roll, and what is the game worth?
- You may re-roll twice, Rs 20 each time. What is the game worth and how does the first-roll bar change?
- The payout is Rs 30 times the face squared. Should you still play at Rs 100, and does the re-roll rule change?
075A company has an enterprise value of Rs 1,000 crore, with net debt of Rs 300 crore and equity worth Rs 700 crore. It raises Rs 200 crore of PIK notes and holds the cash, then pays the cash out as a dividend. What happens to enterprise value and equity value at each step, and later as the PIK interest accrues?Moelis & CompanyLos Angeles · 2026
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Right after the Rs 200 crore of PIK notes is raised and held as cash, what is enterprise value?
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Enterprise value stays at Rs 1,000 crore at every step; only the split between lenders and shareholders moves. Raising Rs 200 crore and holding it leaves net debt at 300 and equity at 700. Paying it out takes net debt to 500 and equity to 500, with shareholders holding the Rs 200 crore in cash. As PIK interest accrues at 10%, the notes grow to 242 after two years and equity falls to 458, value moving to the lenders.
Why does borrowing not change enterprise value?
Suppose your house is worth Rs 1 crore and you take a Rs 20 lakh loan against it, keeping the money in the bank. The house is still worth Rs 1 crore; you owe 20 lakh more and hold 20 lakh more, and your net position is unchanged. Enterprise value is the value of the operating business and does not depend on how it is funded; a financing step only changes who has a claim on that value. Here the PIK notes add 200 of debt and 200 of cash, so net debt stays 300, equity stays 700, and EV stays 1,000.
Enterprise value holds at Rs 1,000 crore through every step: net debt stays 300 when the notes are raised and held, rises to 500 when the Rs 200 crore is paid out, and reaches 542 after two years of 10% accrual, with equity falling from 700 to 500 to 458 as value moves to the lenders. What does the dividend do?
The cash leaves the company and lands in shareholders' pockets. Net debt rises from 300 to 500 because the cash that offset the notes is gone, and equity value falls from 700 to 500. Shareholders are no richer and no poorer: they hold Rs 500 crore of shares plus Rs 200 crore of cash, 700 in all, exactly the 700 they started with. What changed is that the lenders now have a 500 claim ahead of them on the same Rs 1,000 crore of operations, so the equity is riskier and the dividend was financed by that risk.
What happens as the PIK interest accrues?
A PIK noteA loan whose interest is paid in kind: added to the principal each period instead of paid in cash, so the amount owed compounds. charges no cash interest; the coupon is added to the principal. At 10%, the Rs 200 crore becomes 220 after a year and 242 after two. With operations unchanged, EV is still 1,000, so equity is 1,000 - 542 = 458: the 42 of accrued interest is value transferred from shareholders to lenders without a rupee moving. In practice EV does move, but for operating reasons: earnings grow or shrink. Two second-order effects can touch EV through financing: interest that is deductible lowers tax and adds a shield, and heavy leverage raises the chance of distress, which costs value; confirm whether accrued but unpaid interest is deductible under the current tax rules before counting the shield.
The relationshipNet debt borrowings less cash: 300 at the start, 500 after the dividend, 542 after two years of accrual Equity what is left of enterprise value after the lenders' claim What it says in wordsEnterprise value is fixed by the operations; every financing step rearranges the same total between net debt and equity.The trap in the question is the word increase. A candidate who hears PIK and reaches for a bigger EV is adding debt to a number that already includes it. The market capitalisation does fall, from 700 to 500 and then 458, and adding net debt of 500 back to a market cap of 500 gives 1000, the same 1,000. The limit: this holds the operating business fixed to isolate the financing; a real company's EV changes every day for other reasons.
Where candidates lose it
The common loss is answering that EV rises by Rs 200 crore because debt rose. That double counts: EV already contains net debt, and raising cash against new debt leaves net debt where it was. The candidate has confused enterprise value with gross debt plus equity.
The second loss is saying the dividend destroys value. It moves Rs 200 crore from inside the company to its owners and leaves them exactly as wealthy; what it changes is the lenders' claim and the risk of the equity, which is the point to make.
What the interviewer asks next
- The notes carry a 10% cash coupon instead. How does that change cash, net debt and equity each year?
- Why might lenders price a PIK note higher than a cash-pay note of the same size?
- The company uses the Rs 200 crore to buy a business worth Rs 250 crore. What happens to EV and equity now?
Asked at Moelis & Company, Investment Banking, Los Angeles, 2026 (Wall Street Oasis):
Does PIK financing increase or decrease the value of a company's enterprise value?
079Estimate the value of two-wheeler loans disbursed in India in a year.Oaktree Capital ManagementLos Angeles · 2022
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Which three quantities, multiplied, give the annual disbursement?
Show the worked solution
Roughly Rs 70,000 to 75,000 crore a year, on the assumptions below. Start from an assumed 1.8 crore two-wheelers sold a year, assume a little over half are bought on credit, and lend about three quarters of the price. Splitting the market into commuter motorcycles, scooters and premium bikes gives about 99 lakh loans averaging Rs 73,600, or Rs 72,832 crore. Every input is an assumption to state and then confirm.
What is the structure before any number?
To estimate what a college canteen sells on credit, you would count meals, the share put on a tab, and the average tab. Loans work the same way. A finance market size is units times financing penetration times ticket size, and saying that structure first lets the interviewer follow every number after it. Here the units are new two-wheelers sold in a year, penetration is the share bought on a loan, and the ticket is the price less the down payment.
Assume about 1.8 crore two-wheelers are sold in India a year. Treat that as an assumption to confirm against the industry body's current sales data, never a fact to quote. Prices range from a basic commuter bike to a premium motorcycle, so one average price is fragile; split the market three ways instead.
Segment Share of units Price, Rs Bought on a loan Loan to price Loans, lakh Disbursed, Rs crore Commuter motorcycles 55% 85,000 60% 75% 59.4 37,868 Scooters 35% 1,00,000 50% 75% 31.5 23,625 Premium and electric 10% 2,00,000 45% 70% 8.1 11,340 Total 100% 55% 99.0 72,832 Every price, share and loan ratio is an illustrative assumption, not a market statistic. Multiplying units by the share financed and by the loan size in each segment gives about Rs 37,868 crore from commuter motorcycles, Rs 23,625 crore from scooters and Rs 11,340 crore from premium bikes, about Rs 72,832 crore in all. How do you check it a second way?
Run it top-down in one line: 1.8 crore units x 55% financed x 75% of an average Rs 1,00,000 price is Rs 74,250 crore. Two routes landing within about 2% of each other is the check, and the segment split earns its place by showing where the uncertainty lives. The softest input is the financed share: every 5 points on it moves the answer by about Rs 6,621 crore. Then a feel check: 99 lakh loans a year is about 27,123 loans a day across the country, which is plausible for a mass market sold through thousands of dealers.
Say what the number is not. It is a yearly flow of new loans. The loan book outstanding at any time is a stock: with loans running about two and a half years and repaid evenly, the average loan is half outstanding for that period, so the book is roughly 1.25 times a year's disbursement, about Rs 91,041 crore. Used-vehicle loans are excluded.
Where candidates lose it
The fast wrong answer multiplies units by the full price and calls it the loan market: 1.8 crore x Rs 1,00,000 = Rs 180,000 crore, more than double the estimate. It forgets that many buyers pay cash and that borrowers put down a deposit.
The second loss is quoting industry figures as if you knew them. Say 'assume about 1.8 crore units a year' and move on; the interviewer is marking the structure, the second route and the sanity check, not your memory of a statistic.
What the interviewer asks next
- How does the answer change if electric two-wheelers rise to a quarter of units?
- What is the outstanding loan book, rather than the annual disbursement, and why does the difference matter to a lender?
- Which input would you research first, and where would you look?
Asked at Oaktree Capital Management, Corporate Finance, Los Angeles, 2022 (Wall Street Oasis):
First round with recruiter, mostly behavioral with a few questions about market sizing
082Two companies each have revenue of Rs 1,000 crore, EBIT of Rs 100 crore and Rs 500 crore of debt at 10%. Company A has fixed operating costs of Rs 600 crore; company B has Rs 100 crore, with the rest of each cost base variable. Revenue falls 20% at both. What happens to each company's lenders and to each company's shareholders?Oaktree Capital ManagementLos Angeles · 2024
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After the 20% fall, what is company A's EBIT?
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A's lenders are in trouble and B's are merely uncomfortable; both sets of shareholders take a far bigger hit than revenue. A's EBIT swings from Rs 100 crore to minus Rs 40 crore and cannot cover Rs 50 crore of interest. B's falls to Rs 60 crore and covers it 1.2 times. Profit before tax falls 280% at A and 80% at B: operating and financial leverage multiply.
Why do identical profits hide very different risks?
Take two tea stalls that each clear Rs 10,000 a month. One rents a shop for Rs 60,000 a month and buys cheap; the other rents a cart for Rs 10,000 and pays more per cup. In a good month they look the same. In a bad month the shop's rent is still due while the cart's costs fall with its sales. Fixed costs do not shrink when revenue does, so the higher the fixed share of costs, the more of every lost rupee of revenue comes straight out of profit. That sensitivity is operating leverage.
Work out each company's variable cost. A spends Rs 900 crore to make Rs 100 crore of EBIT; Rs 600 crore of that is fixed, so Rs 300 crore, or 30% of revenue, is variable. B's Rs 900 crore is Rs 100 crore fixed and Rs 800 crore variable, 80% of revenue. So a lost rupee of revenue costs A 70 paise of EBIT and B only 20 paise. Revenue falls by Rs 200 crore: A loses Rs 140 crore of EBIT, B loses Rs 40 crore.
After the same 20% fall in revenue, company A's EBIT turns to minus Rs 40 crore against Rs 50 crore of interest, while company B's falls to Rs 60 crore and still covers interest 1.2 times, because A's costs are mostly fixed. What does each lender actually face?
Each lender is owed Rs 50 crore of interest a year, 10% on Rs 500 crore. B's lender is paid out of operating profit with Rs 10 crore to spare: thin, and a rating analyst would note coverage dropping from 2.0x to 1.2x, but no default. A's lender is not paid from operations at all. A must find Rs 90 crore of cash, Rs 50 crore of interest plus the Rs 40 crore operating loss, from its cash balance, an asset sale or new borrowing, so its lender's safety now depends on liquidity, not earnings. A's break-even revenue to cover interest is Rs 929 crore, just 7% below today; B's is Rs 750 crore, 25% below.
The relationshipDOL degree of operating leverage: per cent change in EBIT for a 1% change in revenue DFL degree of financial leverage: per cent change in profit before tax for a 1% change in EBIT Contribution revenue less variable costs: Rs 700 crore at A, Rs 200 crore at B What it says in wordsTotal leverage is operating leverage times financial leverage, so a 20% revenue fall cuts profit before tax by 20 x 14 = 280% at A and 20 x 4 = 80% at B.Why do shareholders and lenders feel operating leverage differently?
Run revenue up 20% as well as down. A's profit before tax jumps from Rs 50 crore to Rs 190 crore and B's to Rs 90 crore. A's shareholders get the steep line both ways, and their loss is capped at the value of their shares. The lender gets the same Rs 50 crore in the good year and the base year, and loses only in the bad year, so operating leverage hands the upside to equity and the downside to debt. That is why credit analysts ask about the fixed cost base before they ask about margins, and why lenders to high fixed cost businesses ask for lower debt or tighter covenants.
Both companies earn Rs 50 crore before tax at Rs 1,000 crore of revenue, but A's profit line is 3.5 times as steep as B's, swinging from minus Rs 90 crore to plus Rs 190 crore, while the lender to either receives only its fixed Rs 50 crore. The limitation: real fixed costs are not perfectly fixed. A could cut overheads, defer maintenance or renegotiate rent within a few quarters, so the first year is the dangerous one. Say that, and the answer moves from a formula to a judgement.
Where candidates lose it
The common error is assuming profit falls in line with revenue: 20% off Rs 100 crore of EBIT gives Rs 80 crore for both companies, and the candidate concludes nothing changes. The question gave the fixed cost split precisely so you would compute the variable cost ratio first and see that A loses 70 paise per rupee.
The second loss is talking only about equity. The question asks about lenders too, and their position is asymmetric: no extra reward when revenue rises, full exposure when fixed costs bite. Name interest coverage, the cash shortfall and the break-even revenue, and you have answered as a credit analyst would.
What the interviewer asks next
- How much debt could A carry and still cover interest 1.5 times after a 20% revenue fall?
- A wants to convert Rs 300 crore of fixed costs to variable through outsourcing at a higher unit cost. How does that change its lender's view?
- Why do lenders to airlines and hotels typically accept lower debt multiples than lenders to distributors?
Asked at Oaktree Capital Management, Credit, Los Angeles, 2024 (Wall Street Oasis):
How does operating leverage affect debt vs. equity holders
083A phone sells for Rs 57,000 cash today, or on a 'no-cost EMI' of Rs 10,000 a month for six months, the first instalment due a month from now. What interest rate is hidden in the EMI?Bank creditCorporate FP&A
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Roughly what annual rate is hidden in the EMI?
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About 1.49% a month, or 19.4% a year effective. The real price is the Rs 57,000 cash price, so choosing the EMI means borrowing Rs 57,000 and repaying Rs 60,000 in six monthly instalments. The rate that makes six payments of Rs 10,000 worth exactly Rs 57,000 today is 1.49% a month. The forgone Rs 3,000 discount is the interest, charged on a balance that shrinks every month.
Where is the interest, if the EMI says no-cost?
A friend offers to sell you his bike for Rs 57,000 today, or for Rs 60,000 paid over six months. Nobody calls the second option interest-free; it is a loan of Rs 57,000 with Rs 3,000 of interest. A shop doing the same thing is no different. When a cash discount is available, the discount you give up by paying in instalments is the interest on the loan. The 'no-cost' label means the instalments add up to the sticker price, not that money has no time value.
So the question becomes: at what monthly rate is a stream of six Rs 10,000 payments, starting in one month, worth Rs 57,000 today? That is the internal rate of return of the loan.
The relationshipr the monthly interest rate hidden in the instalments k the month each Rs 10,000 instalment is paid What it says in wordsThe hidden rate is the one that discounts the six instalments back to the cash price.Six Rs 10,000 instalments add to Rs 60,000 at face value, but discounted at 1.49% a month they are worth exactly the Rs 57,000 cash price, so the Rs 3,000 discount given up is interest at 19.4% a year effective. How do you solve it without a spreadsheet?
Guess and check. The annuity factor must be 57,000 / 10,000 = 5.70. At 1% a month, six payments are worth 5.80 times one payment; at 2% they are worth 5.60. Halfway gives about 1.5%, and 1.5% gives 5.697, a whisker under 5.70, so the answer is just below: 1.49%. Then compound, do not multiply: 1.0149 to the power 12 is 1.194, so the effective annual rate is 19.4%, against 17.8% if you simply multiply by 12.
A second check uses the average balance. The loan starts at Rs 57,000 and is paid down to zero over six months; the balance at the start of each month averages about Rs 33,700. Rs 3,000 of interest on about Rs 33,700 over six months is 8.9%, or about 17.8% a year simple, which matches 1.49% x 12.
What changes the answer in real life?
Timing matters a great deal. If the first instalment is due today rather than in a month, you really borrow only Rs 47,000 and repay Rs 50,000 over five months, and the hidden rate jumps to 2.10% a month, about 28% a year. Any processing fee, or tax charged on the interest component, raises the true cost further, so always ask what you pay on day one. Check the specific charges and the current tax treatment with the lender. And if there was never a cash discount to forgo, the EMI really is close to free for the buyer, because the retailer, not the buyer, is paying the lender.
Where candidates lose it
The quick wrong answer is about 5%: Rs 3,000 on Rs 57,000. Some candidates double it to 10.5% for a year and feel careful. Both ignore that the loan is repaid monthly, so the average balance is only a little over half of Rs 57,000, and the rate on what is actually owed is far higher than the headline.
The second loss is multiplying the monthly rate by 12 and calling it the annual rate. 17.8% is a nominal rate; money compounding monthly at 1.49% grows 19.4% in a year. Give both and name which is which.
What the interviewer asks next
- If the first instalment is paid at purchase, what is the hidden rate? (About 2.1% a month.)
- The cash discount is only Rs 1,000. What is the hidden rate now, roughly?
- Who pays the lender when the retailer offers no cash discount at all, and why would the retailer do that?
090A company has net income of Rs 300 crore and 10 crore shares. It also has Rs 500 crore of 6% convertible bonds, convertible at Rs 250 a share. The tax rate is 25%. What is basic EPS, what is diluted EPS on the if-converted method, and what happens to each statement if the bonds actually convert?Equity researchBig Four
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How many new shares does conversion create?
Show the worked solution
Basic EPS is Rs 30.0; diluted EPS is Rs 26.88, about 10% lower. The if-converted method assumes conversion: add back the after-tax interest saved, Rs 30 crore x 0.75 = Rs 22.5 crore, and add 2 crore shares. That gives Rs 322.5 crore over 12 crore shares. On actual conversion, debt falls Rs 500 crore and equity rises Rs 500 crore, interest expense stops, and no cash changes hands.
What does the if-converted method assume?
Imagine a friend lent your shop Rs 5 lakh and can choose, any time, to swap the loan for a share of the business. To be honest with your other partners about what each share is worth, you would show the numbers as if the friend has already swapped: no more interest to pay, but one more partner splitting the profit. Diluted EPS shows earnings per share as if every convertible security that would reduce EPS had already converted, adding back the interest it would save and adding the shares it would create.
The interest is Rs 500 crore x 6% = Rs 30 crore a year. It was tax-deductible, so removing it raises net income by only Rs 30 crore x (1 minus 25%) = Rs 22.5 crore. Conversion creates Rs 500 crore / Rs 250 = 2 crore shares. Diluted EPS is (300 + 22.5) / (10 + 2) = Rs 26.875, which rounds to Rs 26.88.
The relationshipNI net income, Rs 300 crore I annual interest on the convertible, Rs 30 crore N existing shares, 10 crore F / P_c face value over conversion price, the new shares What it says in wordsAdd the after-tax interest saved to earnings and the conversion shares to the share count.Conversion lifts earnings by 7.5% but the share count by 20%, because each new share brings only Rs 11.25 of saved after-tax interest against Rs 30 earned by each existing share, so diluted EPS falls to Rs 26.88. How do you know whether a convertible dilutes?
Compare what each new share brings with what each existing share earns. Each conversion share brings Rs 22.5 crore / 2 crore = Rs 11.25 of earnings, far below basic EPS of Rs 30, so including the convertible lowers EPS and it must be counted. If basic EPS were below Rs 11.25, conversion would raise EPS; that security is anti-dilutive and is left out of diluted EPS. The test is per security, so a company with several convertibles ranks them from most to least dilutive.
What happens to each statement on actual conversion?
Balance sheet: borrowings fall Rs 500 crore and equity rises Rs 500 crore, split between share capital at face value and securities premium. Total assets do not move; the right-hand side changes its mix and leverage falls sharply. Income statement: from the conversion date, the Rs 30 crore of interest stops, so profit rises Rs 22.5 crore after tax. Cash flow statement: nothing at conversion, because no cash changes hands; it is disclosed as a non-cash transaction. Afterwards, the Rs 30 crore of cash interest is no longer paid. Reported basic EPS after conversion should land close to the diluted EPS already shown, which is why analysts value on the diluted figure.
Where candidates lose it
The common error is adding the full Rs 30 crore of interest back to earnings. Interest was tax-deductible, so saving it also loses the tax shield: only Rs 22.5 crore reaches net income. Using Rs 30 crore gives Rs 27.50 instead of Rs 26.88.
The second loss is the statement walk. Candidates say cash falls by Rs 500 crore to repay the bond, but conversion repays nothing in cash: the bondholders take shares instead. Debt becomes equity, the balance sheet total stays put, and the cash flow statement shows nothing on the day.
What the interviewer asks next
- At what level of net income would this convertible become anti-dilutive?
- The company also has options on 1 crore shares at Rs 200, and the share price is Rs 300. How do they enter diluted EPS?
- Why might a company prefer issuing a convertible to straight debt, and what does it give up?
092A 10-year zero-coupon bond and a 10-year bond paying an 8% annual coupon both yield 8%. Yields rise by one percentage point. Which bond's price falls more, by roughly how much, and why?BarclaysLondon · 2025PIMCOLondon · 2022AmundiLondon · 2018
Try it first
Same maturity, same yield. Which falls more when yields rise?
Show the worked solution
The zero falls more: about 8.8% against about 6.4% for the coupon bond. Price sensitivity follows duration, the present-value-weighted average time to each cash flow. The zero's only cash flow is at year 10, so its duration is 10 years. The coupon bond returns part of its value early, so its duration is 7.25 years. Modified duration predicts falls of 9.26% and 6.71%; convexity makes the actual falls slightly smaller.
Why does the timing of cash flows decide the sensitivity?
Two friends each owe you Rs 1,000 in total. One will repay it all in ten years; the other pays Rs 80 a year and the rest at the end. If prices start rising faster and money loses value faster, which IOU loses more value? The one where every rupee is ten years away. The second friend's early payments are already in your hands and can be reinvested at the new higher rates. A bond's price sensitivity to yield depends on when its value arrives on average, not on its final maturity date. That average, weighted by present value, is the Macaulay duration.
Drawn as present values on a timeline, the coupon bond's cash flows balance at 7.25 years because the coupons pull the weight earlier, while the zero-coupon bond has all its value at year 10 and a duration of exactly 10 years. How big is each fall?
Use modified duration, Macaulay duration divided by one plus the yield, as the percentage price change per point of yield. For the zero, 10 / 1.08 = 9.26; for the coupon bond, 7.25 / 1.08 = 6.71. So a one point rise should cut prices by about 9.3% and 6.7%. Repricing exactly: the zero goes from 46.32 to 42.24, down 8.80%; the coupon bond goes from par, 100.00, to 93.58, down 6.42%.
The relationshipD_Mac Macaulay duration: present-value-weighted average time to the cash flows, in years y the yield, 8% \Delta y the change in yield, one percentage point What it says in wordsThe percentage price change is roughly minus modified duration times the change in yield.Rebased to 100 at an 8% yield, the zero's price curve is steeper than the coupon bond's, so a rise to 9% cuts the zero by 8.8% and the coupon bond by 6.4%, each a little less than the straight-line duration estimate because the curves bow outward. Why are the actual falls smaller than duration predicts?
Duration is the slope of the price curve at today's yield, a straight-line estimate. The real curve bows outward, so as yields rise each further step hurts a little less, and as yields fall each step helps a little more. That curvature, convexity, makes a plain bond fall less than duration predicts when yields rise and gain more than predicted when they fall. For a one point move the gap is small, under half a point here; for larger moves, add the convexity term or simply reprice the bond.
Two practical notes. Most Indian government bonds pay coupons twice a year, which shortens the duration slightly but leaves the answer unchanged. And the gap between the bonds widens with maturity and narrows as coupons fall: a coupon bond's duration always sits below its maturity, while a zero's always equals it.
Where candidates lose it
The common wrong answer is 'the same, both are ten-year bonds'. Maturity tells you when the last payment arrives; duration tells you when the value arrives. Interviewers ask this exact pair to see whether you know the difference.
The second loss is giving the direction without a size, or quoting duration as the answer to the decimal. The strong answer gives the modified duration estimate, about 9.3% against 6.7%, then says the actual falls are a little smaller because of convexity, and names why the coupons shorten the duration.
What the interviewer asks next
- What would the coupon bond's duration be if it paid a 12% coupon instead: longer or shorter than 7.25 years?
- A bank funds 10-year fixed-rate loans with one-year deposits. What happens to its value when rates rise one point?
- Why can a callable bond's effective duration fall as yields fall?
Asked at Barclays, Sales and Trading, London, 2025 (Wall Street Oasis):
Regarding interest rate duration for certain products and how it changes based on maturity, tenor etc
Asked at PIMCO, Sales, London, 2022 (Wall Street Oasis):Typically the product interview was toughest with questions regarding applications of duration
Asked at Amundi, Rates, London, 2018 (Wall Street Oasis):What would your allocation be in today's market? What is effective duration?
096Branch A has a lower default rate than branch B among salaried borrowers, and a lower rate among self-employed borrowers, yet a higher overall default rate. A lent to 100 salaried borrowers who defaulted at 2% and 900 self-employed who defaulted at 10%. B lent to 900 salaried at 3% and 100 self-employed at 12%. Show how this is possible, and say which branch underwrites better.Bank creditRating agencies
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Before you compute: which branch has the higher overall default rate?
Show the worked solution
A's overall rate is 9.2%, B's is 3.9%, and A is still the better underwriter in each segment. A: 2 defaults among 100 salaried plus 90 among 900 self-employed, 92 in 1,000. B: 27 plus 12, 39 in 1,000. An overall rate is a weighted average of segment rates, and the weights are the mix of the book. A's book is 90% self-employed, where everyone's rate is high, so its average is pulled up by whom it lends to, not by how well it lends.
How can a branch be better at everything and worse in total?
Two surgeons. One takes the hardest cases in the hospital and loses fewer of them than anyone else would; the other takes mostly routine cases. Count deaths per patient and the first surgeon looks worse, because her patients were sicker to begin with. An overall rate is a weighted average of segment rates, and the weights are the mix of the book, so a branch that lends mostly to the riskier segment carries a higher average even when it is better in every segment. A's rate is 0.1 x 2% + 0.9 x 10% = 9.2%; B's is 0.9 x 3% + 0.1 x 12% = 3.9%.
Segment Branch A Branch B Lower rate Salaried 100 loans, 2%, 2 defaults 900 loans, 3%, 27 defaults A Self-employed 900 loans, 10%, 90 defaults 100 loans, 12%, 12 defaults A Whole book 1,000 loans, 9.2%, 92 defaults 1,000 loans, 3.9%, 39 defaults B A beats B in each segment and loses on the whole book because its mix is nine tenths self-employed. Drawn with width as the number of loans and height as the default rate, A's book is one wide bar at 10% and a sliver at 2%, averaging 9.2%, while B's is one wide bar at 3% and a sliver at 12%, averaging 3.9%, so A is better in both segments and worse overall. How do you compare the two branches fairly?
Give them the same customers. Apply each branch's segment rates to one common mix and the mix stops voting. At B's mix, 90% salaried, A's rates give 0.9 x 2% + 0.1 x 10% = 2.8% against B's actual 3.9%. At A's mix, B's rates give 0.1 x 3% + 0.9 x 12% = 11.1% against A's actual 9.2%. At a 50:50 mix, A is 6.0% and B is 7.5%. On any common mix A is lower, so A underwrites better; its higher total is the price of the book it chose to build. This reversal, where a comparison flips when groups are combined, is known as Simpson's paradox.
The relationshipw_i the share of the book in segment i, the mix r_i the default rate within segment i What it says in wordsThe overall default rate is each segment's rate weighted by its share of the loans, so the mix can outweigh the rates.What should the analyst say beyond the arithmetic?
Three things. First, both statements are true at once: A underwrites better, and A's book loses more money, because capital is charged on actual losses and A chose a riskier book. Whether that was a good choice depends on the pricing: if A earns enough extra yield on self-employed loans to cover the extra 8 points of defaults, its strategy can be sound. Second, ask why the mixes differ, since location, product and targets all shape who walks in. Before judging two rates, ask whether the two populations are the same; if they are not, standardise to one mix or compare segment by segment.
Third, say the limitation. Each segment is itself a mix: of loan sizes, vintages and cities. A's salaried borrowers might be larger-ticket government employees and B's might be gig workers on salary slips, and a finer split could flip the comparison back. Standardising to the segments you can see removes the mix you know about, never the mix you do not. The honest close is that A looks the better underwriter on this cut, and you would want the segment rates by vintage before signing that view.
Where candidates lose it
The common failure is disbelief: candidates assume the overall rates must be wrong, or declare that B is the better underwriter because its total is lower. Do the two weighted averages aloud, 0.1 x 2 + 0.9 x 10 and 0.9 x 3 + 0.1 x 12, and the paradox dissolves into mix.
The second loss is stopping at the explanation. The interviewer wants the fair comparison: put both branches on one mix and A is lower on every one (2.8% against 3.9% at B's mix). Then add that A's book still loses more rupees, which is a question about strategy and pricing, not underwriting skill.
What the interviewer asks next
- If A charges self-employed borrowers 4 points more interest than salaried ones, is its riskier book a sound strategy?
- What single number would you report to the credit committee to compare the two branches' underwriting?
- Give another finance example where combining groups reverses a comparison.
097A stock trades at 30 times next year's earnings. Its cost of equity is 12%, and it earns a 20% return on the profit it reinvests. What perpetual growth rate is the market pricing in?Equity researchBuy-side research
Try it first
What does the 30x multiple say about growth?
Show the worked solution
About 10.4% a year, forever, with the company paying out 48% of its earnings. A forward P/E equals the payout ratio divided by the cost of equity less growth, and with a fixed ROE the payout is set by growth: payout = 1 minus g/ROE. So 30 = (1 minus g/0.20) / (0.12 minus g). Multiply out: 3.6 minus 30g = 1 minus 5g, so 25g = 2.6 and g = 10.4%. Check: a dividend yield of 48% / 30 = 1.6% plus 10.4% growth is the 12% cost of equity.
Where does a multiple hide a growth forecast?
If someone offers to sell you a shop for thirty years of its current profit, they are not quoting a price; they are telling you how fast they expect the profit to grow. The multiple is the forecast. Under the Gordon growth model a share is worth next year's dividend over (r minus g), so dividing by next year's earnings gives P/E = payout / (r minus g), and a given P/E can be solved for g. The one thing people forget is that the payout is not free to choose: growth has to be paid for with retained profit.
With a fixed return on reinvested profit, growth equals ROE times the retention rate, so retention is g/ROE and payout is 1 minus g/ROE. At a 20% ROE, growing at 10% means keeping half the earnings. Put that into the multiple: 30 = (1 minus 5g) / (0.12 minus g). Cross-multiply: 3.6 minus 30g = 1 minus 5g, so 2.6 = 25g and g = 10.4%. The implied payout is 1 minus 0.104/0.20 = 48%, and the implied dividend yield is 48% of a 3.33% earnings yield, 1.6%.
The relationshipP0 / E1 the forward P/E, price over next year's earnings 1 minus g/ROE the payout ratio once growth is funded from retained profit r the cost of equity, 12% g the perpetual growth rate the price implies What it says in wordsThe forward P/E is the payout ratio over the gap between cost of equity and growth, and the payout is whatever is left after funding growth at the ROE.At a 12% cost of equity and a 20% ROE, the P/E curve starts at 8.3x with no growth, passes 15x at 8% and 25x at 10%, and crosses 30x at 10.4%, while at a 15% ROE the same 30x needs 11.1% because more of each rupee must be retained to grow. Why does the ROE matter as much as the growth rate?
Because the ROE sets how much growth costs. At a 15% ROE the same 30x needs 11.1% growth, since a bigger share of earnings has to be retained to fund each point of it. At an ROE equal to the cost of equity, 12%, the multiple is 1/r = 8.3x whatever the growth rate, because every retained rupee earns exactly what shareholders could earn elsewhere. Growth adds value only when the reinvested profit earns more than the cost of equity; the multiple prices the spread between ROE and r as much as it prices g. The curve is also steep near the answer: at 10% the multiple is 25x, at 11% it is 45x, so a 30x stock is one point of growth away from either 25x or 45x.
Now say the limitation. 10.4% growth forever, only 1.6 points below the discount rate, is not a forecast anyone would defend; no company outgrows the economy indefinitely. The honest reading is that 30x prices a long period of fast growth that will fade, and a two-stage model, say 10.4% for a decade and a lower rate after, is the next thing to build. The one-line solve is still worth doing, because it converts a multiple into a sentence you can argue with: the market expects this company to compound earnings at about 10% for a very long time while earning 20% on what it retains.
Where candidates lose it
The common slip is using P/E = 1 / (r minus g), which gives 30 = 1 / (0.12 minus g) and g = 8.7%. That formula pays out every rupee and still grows, which is impossible: growth has to be funded. Put the payout in as 1 minus g/ROE and the answer moves to 10.4%.
The second loss is reporting the number as a forecast. It is what the price implies, not what will happen, and it rests on three assumptions the interviewer wants named: a constant 20% ROE on new investment, a 12% cost of equity, and growth held forever at a rate no company sustains.
What the interviewer asks next
- If the return on new investment falls to 12%, what multiple is justified at any growth rate, and why?
- The stock pays out 48% of earnings. What dividend yield does that give at 30x, and how does it reconcile with the 12% cost of equity?
- How would you restate the implied growth as ten years of fast growth followed by 4% forever?
100You toss a fair coin until you see two heads in a row. How many tosses do you expect to need? And why is that more than the number you expect to wait for a head followed by a tail?Consulting-style caseKPO research support
Try it first
Which pattern takes longer on average to appear, HH or HT?
Show the worked solution
Six tosses for HH on average, four for HT. For HH, a tail after a head sends you back to the start with nothing. For HT, once you hold a head, every further head keeps you one toss from finishing, so nothing is lost. Solve HH with two unknowns: from the start E0 = 1 + E0/2 + E1/2, and after a head E1 = 1 + E0/2, which gives E1 = 4 and E0 = 6. For HT, E1 = 1 + E1/2 = 2 and E0 = 4.
Why is waiting for two heads different from waiting for a head then a tail?
Suppose you will go trekking after two dry days in a row. One wet day after a dry one puts you back to zero: you need two fresh dry days. Now suppose instead you are waiting for a dry day followed by a wet one. Extra dry days cost nothing; you stay ready, and the first wet day finishes the job. A failed attempt at HH throws away the progress you had, while a failed attempt at HT keeps it, so HH pays for its failures twice: the wasted toss and the lost head. That asymmetry is the whole answer; the algebra just prices it.
Write the states. E0 is the expected tosses still needed from nothing, E1 from one head in hand. From nothing, one toss is spent and you land back at E0 with a tail or at E1 with a head: E0 = 1 + E0/2 + E1/2, so E0 = 2 + E1. For HH, from one head a head finishes and a tail drops you to E0: E1 = 1 + E0/2. Substitute: E1 = 1 + (2 + E1)/2, so E1/2 = 2, E1 = 4 and E0 = 6. For HT, from one head a tail finishes and a head keeps you at E1: E1 = 1 + E1/2, so E1 = 2 and E0 = 4.
The relationshipE0 expected tosses still needed with no useful toss in hand E1 expected tosses still needed holding one head 1/2 the chance of a head, and of a tail, on a fair coin What it says in wordsEach state's expected wait is one toss plus the average of the waits in the states a head and a tail lead to.In the HH diagram the tail arrow from the one-head state runs all the way back to the start, which is why the wait is 6 tosses, while in the HT diagram a head from the one-head state only loops in place, so the wait is 4. Is there a rule for longer patterns?
Yes, and it is quick enough for the room. For each length k at which the pattern's first k symbols equal its last k symbols, add 2 to the power k. HH matches itself at k = 1 (H and H) and at k = 2 (the whole thing): 2 + 4 = 6. HT matches itself only at k = 2: 4. HHH gives 2 + 4 + 8 = 14; HTH gives 2 + 8 = 10; HTT gives just 8. Patterns that overlap with themselves take longer to appear from a fresh start, because their occurrences come in clusters, and the same long-run frequency spread into clusters means longer gaps between them. Every pattern of length n shows up once in 2 to the n positions on average; what differs is how bunched those appearances are.
The average hides a wide spread. The chance that HH has not appeared after ten tosses is 14.1%, against 1.1% for HT, so one game in seven is still running at toss ten when you wait for HH. And the figures assume a fair, independent coin: with heads at 60%, the HH wait falls to 1/p + 1/p squared, about 4.4 tosses. The finance link is any rule that needs consecutive results, such as a bonus or a covenant test that requires two good quarters in a row: one bad quarter resets the count, so the rule is harder to satisfy than its two-in-four odds suggest.
Where candidates lose it
The common wrong answer is 4 for both, from 'each pattern has probability 1/4, so wait 4 tosses'. That is the long-run frequency, not the wait from a fresh start, and it ignores that a failed HH attempt destroys the head you had. Another is 8, from doubling the single-head wait of 2 and then adding; the state equations, not intuition, settle it at 6.
The second loss is reaching 6 and 4 with no reason. The interviewer asked why, and the one-sentence answer is that HT keeps its progress after a failure and HH does not. Offer the overlap rule afterwards: it shows you can extend the result to HHH or HTH without starting over.
What the interviewer asks next
- How many tosses do you expect to wait for HHH, and for HTH?
- Two players toss one coin: one wins if HH appears first, the other if HT appears first. Who is more likely to win?
- With a coin that shows heads 60% of the time, what is the expected wait for HH?
