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Warburg Pincus Private Equity Case Study

Project Oakstead — 3-Hour Full LBO with an IPO Exit

A 3-hour Full LBO Modeling Test case study with a complete model answer

180
Minute Format
2
Deliverables
7
Concepts Tested
Advanced
Difficulty

Modeled After

Warburg Pincus

The full LBO exercise Warburg Pincus is reported to set from a case packet rather than a workbook shell: a staple capital structure carrying an original issue discount, an undrawn commitment fee on the revolver and a PIK toggle, employee option tranches by strike, an exit executed as a staged IPO sell-down with underwriting and secondary discounts, and a closing question asking the highest price the candidate would pay.

Structure and exercise format are modeled after Warburg Pincus — the case-packet format the firm is reported to use. The company, the financing, the offering and every figure in this case are entirely our own.

The Situation

Oakstead Precision Components, Inc. machines and finishes close-tolerance metal components and sub-assemblies for three end markets: vacuum-chamber hardware and gas-delivery bodies for semiconductor capital equipment, implantable-grade housings for medical devices, and structural fittings for commercial aerospace.

Oakstead Precision Components

Sector
Industrials — precision machining and finishing of close-tolerance metal components and sub-assemblies for semiconductor capital equipment, medical devices and commercial aerospace
Size
Geography
United States
Ownership
Situation

The Prompt

You are a candidate working through a three-hour take-home at a private equity firm. The packet arrives with a labeled workbook shell attached.

180 minutesLBO Modeling TestsModeling

Supporting Materials

What you are handed at the start of the case, in the format a real process would use.

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  • Case packet and directions (material-1.pdf)

  • Information package (material-2.pdf)

  • Financing term sheet and offering terms (material-3.pdf)

  • Blank workbook template (template.xlsx)

What You Have to Produce

The deliverables, in the order the committee will read them. The exercise runs 180 minutes.

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  1. PART 1

    Operating Model — volume times price, three cases, and the depreciation staircase

  2. PART 2

    Transaction — sources, uses and the opening balance sheet

  3. PART 3

    Income statement — seven projected years, every interest line separately

  4. PART 4

    Balance sheet — seven years, a check row in each

  5. PART 5

    Cash flow statement — four non-cash add-backs, not one

  6. PART 6

    Debt schedule — the floor, the discount, the election and the sweep

  7. PART 7

    Returns — the offering, the sell-down, the ladder, the solve and the price

  8. PART 8

    The written page — the highest price you would pay

How to Approach It

The order a strong candidate works in, and why. This is the shape of the answer — the finished Excel model and memo are in the solution set below.

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  1. 0 – 20 min

    read the packet, do not type

  2. 20 – 45 min

    the operating model and the staircase

  3. 45 – 65 min

    the transaction and the opening balance sheet

  4. 65 – 95 min

    the income statement to EBIT, then the cash flow to the line before debt service

  5. 95 – 135 min

    the debt schedule

  6. 135 – 145 min

    link interest back, and close the balance sheet

  7. 145 – 175 min

    the returns tab

  8. 175 – 180 min

    the page

Key Concepts

The ideas this case is built on. Know these cold and the case becomes a question of execution rather than knowledge.

Original issue discount: fund the uses with proceeds, not face

A tranche issued below par raises less cash than its face value. Interest, amortization and repayment all run off the face amount, but only the net proceeds are available to fund the uses. Size the sources off face and the sources column overstates the cash raised, the equity plug is understated by exactly the discount, and the opening balance sheet does not close in any year. It is a small number that breaks a large tab, and because the equity check is the plug it hides inside the one figure the whole return is measured against.

The discount is a contra-liability, not an asset

Since the current presentation took effect, debt issuance costs and original issue discount are direct deductions from the carrying amount of the debt rather than deferred assets. The balance sheet therefore carries the paper at face less what has not yet accreted, and that number is smaller than par for the whole life of the deal. Two numbers, both correct, describe the same debt, and knowing which one belongs where is most of what this mechanic tests.

Two accretion conventions, and why they differ

A fixed-rate bullet has a determinable set of cash flows, so it has a yield to maturity and the effective interest method applies: interest expense is the carrying amount times the yield, the cash coupon is the face times the coupon, and the difference is accretion that raises the carrying amount every year without a dollar being borrowed. A floating tranche that amortizes and is swept has no knowable balance path, so no yield exists to strike an effective rate on, and the credit agreement amortizes its discount straight-line over the remaining life instead.

The write-off on a repayment ahead of schedule

Prepaying a term loan issued at a discount accelerates the pro-rata share of the remaining discount into that year's interest expense — and the same happens to the unamortized issuance costs. It is a real charge on the income statement in the year the principal goes out, it is non-cash, and it comes back on the cash flow statement. A model whose discount amortizes on a straight line and never reacts to a sweep has missed a charge that peaks in the year the offering's proceeds land on top of it.

Cash interest and total interest expense are different questions

Cash interest is what the business pays and what a credit committee sizes coverage on. Total interest expense is what the income statement carries, and on a structure like this one it is materially larger because four of its lines are non-cash: the payment in kind, the accretion of the discount, the amortization of the issuance costs and the write-off on prepayment. Print the two subtotals separately. A reader who cannot see the difference cannot tell whether the coverage ratio in front of them is the one a lender would quote.

The yield to maturity exceeds the coupon, and that is checkable

Paper issued below par yields more than it pays. The gap between the quoted yield and the stated coupon is exactly what the discount is worth expressed as a rate, and it is provable in one row: discount the coupons and the principal at the quoted yield and you should recover the issue proceeds. Build that check. It takes ninety seconds and it certifies the whole accretion schedule underneath it.

Every ratio is struck on par, never on carrying value

Leverage tests, the excess cash flow calculation, the toggle election and the exit equity bridge are all struck on the par amount of the debt. The carrying value is a presentation matter. Netting the unamortized discount out of net debt when you bridge to equity adds it straight to the equity value, for money the company still owes — and the error survives every tie-out, because the balance sheet still balances. Using the carrying value where a lender or a buyer would use par is an expensive mistake.

A payment-in-kind toggle is an election, not a coupon

Toggle notes pay cash or accrue depending on a test, and the test here is a leverage ratio at the PRIOR year end. Testing on the prior year end is what keeps the election out of a circular reference; testing on the current year end makes the file circular and forces iterative calculation on. Interest coverage can get worse in the year the balance sheet gets better, because deleveraging is what turns the cash coupon on. A model whose coverage ratios rise monotonically in every year has modeled a bond rather than a toggle.

A floored base rate binds when the curve falls through it

Floating tranches price off a base rate subject to a floor, and a forward curve that declines through the projection will cross that floor. Build one effective base rate row as the greater of the curve and the floor and point everything at it. Wire the curve straight into the pricing formulas and the back years of the model are under-costed on every floating tranche at once — a mistake that is right for the first few years, which is why a spot check misses it.

A depreciation staircase, not a percentage of revenue

When the capital program front-loads, depreciation lags it by years and the two move in opposite directions across the plan. Each vintage carries its own straight-line life with a half-year convention in the year it is placed in service, stacking on top of the existing asset base's own remaining charge. Running depreciation off revenue misses the ramp entirely: it understates the tax shield in the back half, overstates net property, plant and equipment, and will not tie to the balance sheet you are also being asked to build.

Earnings quality at both ends of the plan

The add-backs at the front are the familiar half of the question: ask which figure the multiple is on, what the reconciliation contains, and whether each item describes something that stopped or something the business does. The other half is at the back. When a plan carries listed-company costs and stock-based compensation from the first year on the market, those costs sit inside the earnings the offering is priced on. Pricing the book on the year before them, or adding the stock compensation back because it is non-cash, values a company that does not exist.

An exit that is a listing rather than a sale

A sale is one date and one price. A listing is a partial primary and secondary offering priced at a discount to a fully distributed value, a lock-up, and then a series of marketed secondaries at their own discounts and fees. The sponsor is paid on several dates at several prices, and the primary issuance dilutes it permanently at the offering's discounted price. Model each realization separately: the shares sold, the reference price, the discount, the rounded price, the fee and what is left.

A discounted price rounds down to the increment

Books price at clean increments. Take the indicative price — the reference value less the file-to-offer discount — and round it DOWN, never up, because rounding up prices the book above the discount the underwriters said they needed. The effective discount therefore comes out a shade wider than the stated one, and both belong on the page. The same rule applies at every secondary.

A money-weighted return has to be solved, not annualized

The geometric form — proceeds over invested capital raised to the power of one over the hold — assumes a single exit date. With one outflow and several inflows on different dates it is arithmetically wrong, and the return has to be solved. Lay a Newton iteration out as columns: a seed, the present value of the inflows at that rate, the function to be zeroed, its derivative and a corrected rate. Each column reads the one before it, so nothing is circular, no iterative calculation is needed and no banned function appears in the file.

The mark and the money are two different correct numbers

At the offering a fund does not have a result. It has a partial realization and a retained stake, and it has to report both — cash received plus shares marked at the offer price, less what the management plan would take on the part it still holds. That mark is correct on the day it is struck. What happens afterward is more clock, more discounts, more fees and more settlements of the option ladder. Being able to say what stands between the mark and the money, and that all of it was knowable at signing, is what the question is asking for.

A convex option ladder is not a flat percentage

A management plan struck as one pool at one price takes a fixed share of the gain. A ladder of tranches at rising strikes does not: at a low realization price only part of it is in the money, and by a high one all of it is. The payoff is convex in the price, so a flat percentage over-charges the early realizations, under-charges the late ones and gets the total wrong. Settle it tranche by tranche at each realization price and take the share the sponsor actually monetized.

Price discipline as a closed form

'What is the return?' and 'what would you pay?' are different questions. The second holds the return at the hurdle and solves back for the entry multiple. Work out first what the entry price changes: if the paper is fixed in dollars, the exit is priced off a trading multiple and the net debt the plan produces, and the share count and the option ladder are fixed by documents, then none of the sponsor's inflows moves with the price. The equity check that clears a required return is then the present value of those inflows at that return — one row of discount factors rather than a search.

A ceiling truncates; it does not round

A maximum price quoted at two decimals has to be truncated rather than rounded. Rounding a ceiling up produces a price at which your own model returns less than your mandate — a bound the analysis behind it does not support. A bound always rounds toward the side that keeps it true. It is a small piece of craft and it is the difference between a number you can defend in an investment committee and one you cannot.

The route to market is part of the underwriting

Every realization in a staged sell-down is struck below where the stock is marked and pays a fee on top, and the whole program takes years rather than a day. Total those costs once, at the reference prices, and express them as a share of what the stake is worth. Then price the alternatives — one block, two blocks, everything into the offering, a trade sale — and compare them on BOTH measures, because selling faster raises the annualized return and lowers the money. Underwrite the route as well as the business.

What Makes It Hard

The specific traps in this case — the places candidates lose the assessment without noticing.

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Check Your Answer

Type the figures you produced and find out how many are right before you open the worked answer. You get a verdict and, where you are off, a pointer to the part of the build to re-check — never the number itself. Everything you type stays on this device.

How to type a figure. Digits, with an optional unit: 1,234.5, $1,234.5, 2.6x, 21.4%. For a negative use (20.0) or -20.0. Enter as many decimals as you carried — precision is never penalised.

Your Figures

  • $ in millions · graded within ±2%

  • $ in millions · graded within ±2%

  • $ in millions · graded within ±2%

  • $ per share · graded within ±1%

  • $ per share · graded within ±1%

  • $ in millions · graded within ±2%

  • $ in millions · graded within ±2%

  • a multiple — type 2.6 for 2.6x · graded within ±0.5%

  • percent — type 20.0 for 20% · graded within ±1%

  • $ in millions · graded within ±2%

  • percent — type 20.0 for 20% · graded within ±1%

  • $ in millions · graded within ±2%

What the Case Asked For

The arithmetic is only half of it. Tick off what you actually produced — this half is yours to score, because nothing can grade a written recommendation from a checkbox.

The Model Answer

The worked answer in full: Excel model and memo, built the way a banker would actually build them. It is a reference, not a submission — a strong answer under the clock is far shorter.

What the Solution Covers

  • Original issue discount amortization
  • Undrawn revolver commitment fee
  • Base rate floor mechanics
  • Ten option tranches by strike
  • Staged IPO sell-down exit with underwriting and secondary discounts
  • Depreciation staircase per capex vintage
  • Highest price you would pay

Memo

The written recommendation and how it was reached

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The Excel Model

The model is linked and tied out end to end — every schedule, every formula and every check, in the file itself.

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Excel Model and Memo (PDF) — yours to open, edit and rebuild

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Walkthrough

A conversational walkthrough of how to approach the case under time pressure — where to start, what to cut, and how the recommendation gets defended.

Audio Walkthrough

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How to approach Project Oakstead — 3-Hour Full LBO with an IPO Exit

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Frequently Asked Questions

What exactly do I hand in?

The completed workbook and one page justifying the highest price you would pay. The page is not a summary of the model — it is the answer to question three, with the reasoning behind it. Budget twenty-five minutes for it and write it last, but decide what it is going to say while you are building, because the argument comes out of the returns tab rather than out of your head at the end.

In what order should I build the tabs?

Operating model, transaction, income statement down to EBIT, cash flow to the line before debt service, debt schedule in full, then back to fill the interest block, then the balance sheet, then returns. The balance sheet cannot close until the schedules that feed it exist, and the interest block cannot be filled until the debt tab does. Candidates who build strictly left to right stall at the interest lines with half the clock gone and no debt schedule.

Why does the equity check not balance when I total the sources?

Almost certainly because you funded the uses with the face amount of the debt rather than what it actually raises. Two tranches price below par, so the cash available to fund the transaction is smaller than the face outstanding, and the difference is exactly what your equity plug is short by. Read the issue-price column before you total anything, and remember that interest and repayment still run off face.

Is the original issue discount an asset or a deduction from the debt?

A deduction. Both the discount and the debt issuance costs are presented as direct reductions of the carrying amount of the borrowing, not as deferred assets, and that is also the presentation that makes the accretion visible. The balance sheet then carries the paper at face less whatever has not yet accreted, while every leverage test and the exit bridge use par.

Why do the two discounted tranches accrete differently?

Because only one of them has a knowable cash flow. A fixed-rate bullet has a determinable schedule, so a yield to maturity exists and the effective interest method applies. A floating term loan that amortizes and is swept has no knowable balance path, so there is no yield to strike an effective rate on and the credit agreement uses a straight-line convention over the remaining life instead — with a pro-rata write-off whenever principal goes out ahead of schedule.

Should interest be on average or beginning balances?

Beginning, on every tranche, and the directions say so explicitly along with an instruction not to switch on iterative calculation. Average-balance interest is the market convention and is more precise, but it makes the model circular. Beginning balances remove the circularity, which is what lets every check row in the file be trusted. Say on the tab that you know why the convention was chosen, and say which way the difference runs.

How do I model the toggle without making the file circular?

Test it on the PRIOR year end. The election depends on a leverage ratio that the current year's interest would otherwise help determine, which is a circular reference; testing on the previous year's closing balance sheet breaks it cleanly and is how these agreements are actually drafted. Build the ratio as its own row, the election as its own row, and let both coupons multiply through it — then look at what happens to coverage in the year the election flips.

My coverage ratio gets worse in a year the company deleveraged. Is that a bug?

No. When the toggle flips from accrual to cash pay, cash interest jumps in the year the leverage test was passed. The balance sheet got better and the coverage ratio got worse, and the reason is that deleveraging is what turned the coupon on. If your coverage rises smoothly in every year, check whether your election row is doing anything at all.

How do I price the offering?

Take the forward year's Adjusted EBITDA — the one the market will be looking at when the book prices — apply the trading multiple, deduct net debt at par, divide by the pre-offering share count for a fully distributed value per share, apply the file-to-offer discount, and round DOWN to the increment. Print the effective discount as well as the stated one; they are not the same number once you have rounded, and the difference is a real cost to the seller.

Can I just annualize the total proceeds over seven years?

No. That form assumes one exit date, and here the sponsor is paid on four. It will give you a number, and the number will be wrong. Lay out the solve: a seed rate, the present value of the inflows at that rate, the function to be zeroed, its derivative, and a corrected rate — one iteration per column, each reading the one before it. Three or four columns is plenty, and it shows the reader you know why the shortcut does not apply.

What is the difference between the mark and the return?

The mark is what the fund reports at the offering date: cash received plus the retained stake valued at the offer price, less what the management plan would take on the part still held. The return is what the fund eventually receives, over four dates. Both are correct. Everything between them is time, discounts, fees and the option ladder, and all of it was disclosed in the terms the sponsor signed. Being able to state that distinction is worth more than either figure on its own.

How do I answer the price question without searching for it?

Work out what the entry price actually changes. It moves the equity purchase price, the sponsor's check and goodwill — and goodwill is not amortized, so it never reaches the income statement. Every operating line, the whole debt schedule, the offering price and every realization are identical. If none of the inflows moves with the price, the equity check that clears a required return is just their present value at that return, and the enterprise value differs from it by a constant you can compute once. Write the algebra and invert it.

Should the ceiling be rounded or truncated?

Truncated. It is a maximum, and rounding a maximum up quotes a price at which your own model returns less than your mandate. Round toward the side that keeps the bound true. It is a small thing that a reader with judgment will notice immediately, and it costs nothing to get right.

Is anything left out by design that I should mention?

Yes, and naming it with its direction is free marks. At this level of leverage the interest limitation on business interest deductions would bite in the early years and a real structure would carry disallowed interest forward — modeling it would lower the return. No deferred tax movement is modeled, because no write-up is recognized; accelerated tax depreciation would raise it. No over-allotment option is exercised. And the option ladder is held fixed at the entry price rather than re-struck, which flatters the ceiling slightly. Also absent by design: no purchase price allocation, no management rollover, no covenant package and no Excel data tables anywhere.

Does this format still come up?

The three-hour take-home is the version firms use when they want to see judgment as well as mechanics, and the staged-exit variant comes up whenever a sponsor's realistic route out is a listing rather than a sale. It is hard to fake: a discount that accretes correctly, an election that flips on the right test, and a return solved across four dates either work or they do not, and the written page shows whether the candidate understood what they built.

About This Full LBO Modeling Test Case Study

Full LBO Modeling Test case study for private equity interviews. 180-minute format covering original issue discount amortization, undrawn revolver commitment fee, base rate floor mechanics. Includes the full prompt, a tied-out Excel model, a written memo and an audio walkthrough.

This case study sits in Private Equity, under LBO Modeling Tests. Every case ships with the full prompt, the supporting materials, a complete model answer and an audio walkthrough of the judgment behind the recommendation.

180-Minute Format

The time limit a real assessment would give you

Excel Model

Included in the model answer

Memo

Included in the model answer

Audio Walkthrough

How to approach the case under time pressure

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