Investment Banking interview preparation

Questions

100

Traced to a firm

100

Firms

46

Updated

September 2026

Asked at

All firmsTSTruist Securities10Rothschild & Co8Centerview Partners7CSCredit Suisse7HWHarris Williams6Houlihan Lokey6Lazard6Mizuho6Barclays5Citi5Deutsche Bank5Evercore5Moelis & Company5MSMorgan Stanley5Piper Sandler5RCRBC Capital Markets5Goldman Sachs4Nomura4TD Securities4Bank of America3GSGuggenheim Securities3J.P. Morgan3Jefferies3Moody's3Perella Weinberg Partners3WPWarburg Pincus3WBWilliam Blair3HSBC2Lincoln International2Scotiabank2TPTPG2UBS2Wells Fargo Securities2Advent International1Apollo Global Management1Bain Capital1Balyasny Asset Management1BLBlackRock1BPBNP Paribas1General Atlantic1Invesco1Morningstar1PIMCO1STSociété Générale1SSState Street1WMWellington Management1

Topic

All topicsAccounting14Valuation21M&A10Markets and deals10Capital markets3LBO8Leveraged finance3Restructuring2Credit3Debt capital markets2Capital structure2Case and estimation11Brainteasers6Fit5

Level

AnyCoreIntermediateHard

Type

AnyTechnicalCaseBrainteaserFitMarket view

1. 083How would a college increase its revenue?Case and estimationIntermediatetechnicalHWHarris WilliamsInvestment Banking · Richmond · 2018

   Say this

   Price, volume, mix, and new revenue lines. Raise net tuition by discounting less, grow enrolment, shift mix toward full-fee and postgraduate students, and monetise the assets that sit idle.

   Then walk it

   1. Price: the lever is usually the discount rate, not the headline tuition. Most institutions discount heavily; recovering a few points of net tuition is worth more than a sticker price rise and is less visible.
   2. Volume: more students, but constrained by capacity and by admissions standards, since taking weaker students damages the brand that supports the price.
   3. Mix is the highest-return lever. International and out-of-state students pay multiples of the domestic rate. Postgraduate and professional programmes carry better margins. Executive education has almost no marginal cost against existing faculty.
   4. New lines: online programmes that break the capacity constraint entirely, summer and short courses that use the campus in the off-season, conference and event hire, and licensing the brand.
   5. And the asset side: parking, retail on campus, research commercialisation and licensing, plus the fundraising engine, since alumni giving is a genuine revenue line that responds to investment.
   6. The reason mix beats price and volume: operating leverage. Faculty cost is already committed, so an incremental full-fee student in an existing class is almost entirely margin.

   Where candidates lose it

   Listing ideas without ranking them by margin impact. The interviewer wants commercial prioritisation. Naming operating leverage as the reason mix wins turns a brainstorm into an analysis.

   Expect next

   • Which would you do first?
   • What is the risk of the online strategy?
   • How would you value the business after those changes?

   Reported by candidates at Harris Williams (Investment Banking, Richmond, 2018). Source: Wall Street Oasis.

2. 086What are the formulas for net revenue retention, gross retention and churn?Case and estimationIntermediatetechnicalPiper SandlerInvestment Banking · Burlingame · 2026

   Say this

   All three measure the same cohort a year later. Gross retention counts only what you kept, capped at 100 percent. Net retention adds expansion, so it can exceed 100. Churn is the revenue you lost as a percentage of what you started with.

   Then walk it

   1. Gross revenue retention: starting recurring revenue from a cohort, less churn and downgrades, divided by starting revenue. Expansion is excluded, so it can never exceed 100 percent.
   2. Net revenue retention: starting revenue, less churn and downgrades, plus upsell and expansion, divided by starting revenue. Above 100 percent means the base grows by itself.
   3. Gross churn: revenue lost divided by starting revenue. It is one minus gross retention. Logo churn counts customers rather than revenue, and the two can diverge sharply if you lose many small accounts or one large one.
   4. The critical rule: neither retention metric includes revenue from new customers. Mixing new business into retention is the most common error and it flatters the number badly.
   5. Benchmarks worth knowing: best-in-class enterprise SaaS runs gross retention above 90 percent and net above 120. SMB software runs materially lower on both because small customers fail.
   6. Why it matters for valuation: net retention above 110 percent means the business compounds without selling, which is exactly what justifies a high revenue multiple.

   Where candidates lose it

   Including new customer revenue in the retention calculation. It is a cohort metric. And not knowing which one can exceed 100 percent, which immediately reveals whether you have actually used these numbers.

   Expect next

   • What is the rule of forty?
   • Which matters more for valuation, growth or retention?
   • Why can logo churn and revenue churn diverge?

   Reported by candidates at Piper Sandler (Investment Banking, Burlingame, 2026). Source: Wall Street Oasis.

3. 088Comparing two identical buildings, how would you value them differently?Case and estimationIntermediatetechnicalApollo Global ManagementReal Estate · Williamsport · 2022MSMorgan StanleyInvestment Banking · London · 2025

   Say this

   Identical bricks do not mean identical value. The difference is in the leases, the tenants and the debt. Value is net operating income divided by cap rate, and both terms can differ completely for the same building.

   Then walk it

   1. Net operating income first: what rent is actually contracted, at what escalations, with what vacancy and what recoveries of operating expenses. One building leased at above-market rent is worth more than its twin at below-market, today.
   2. Then lease duration and tenant credit. Ten years remaining to an investment grade tenant supports a much lower cap rate than two years remaining to a weak covenant. Duration and credit are the risk in real estate.
   3. Then the cap rate itself, which is where location micro-differences show up: the side of the street, the transport access, the parking, the floor plate efficiency.
   4. Then the debt in place. Assumable below-market fixed-rate debt is a real asset and can be worth several percent of the value. Expensive debt with prepayment penalties is a liability.
   5. Then everything outside the four walls: property tax assessment, ground lease versus freehold, capital expenditure deferred by one owner and not the other, and zoning or development rights above the building.
   6. So the short answer: I would value the cash flows and the risk of those cash flows, not the building. Two identical structures can easily differ 30 percent in value.

   Where candidates lose it

   Assuming the question is a trick with no answer, or listing only location. Leases and tenant credit are the substance. Naming assumable debt is the detail that marks out someone who has looked at real deals.

   Expect next

   • Walk me through getting to exit value from gross potential rent using a cap rate.
   • What is the cash-on-cash return at a given LTV and cap rate?
   • How does a cap rate relate to a multiple?

   Reported by candidates at Apollo Global Management (Real Estate, Williamsport, 2022); Morgan Stanley (Investment Banking, London, 2025). Source: Wall Street Oasis.

4. 092I paint the surface of a 10x10x10 cube green. How many of the small cubes have green on them, and how many do not?BrainteasersIntermediatetechnicalTD SecuritiesGeneralist · New York · 2024

   Say this

   488 have green on them and 512 do not. Solve the easy half first: the unpainted cubes form an inner 8x8x8 block, which is 512. Subtract that from 1,000 to get 488 painted.

   Then walk it

   1. Total small cubes: 10 cubed is 1,000.
   2. Any cube not touching the surface is one layer in from every face. That leaves an 8 by 8 by 8 core, because you remove one layer from each of the two opposite sides in all three dimensions.
   3. 8 cubed is 512 unpainted.
   4. So painted is 1,000 minus 512, which is 488. Computing the painted faces directly is possible but far more error-prone.
   5. If they push further: 8 corner cubes have three painted faces, 96 edge cubes have two, and 384 face cubes have one. That sums to 488, which confirms the answer.

   Where candidates lose it

   Trying to count the painted cubes face by face and double-counting the edges and corners. Always solve for the interior and subtract. Saying 'I will do the easy side first' out loud is itself the signal they want.

   Expect next

   • How many have exactly two painted faces?
   • Generalise it for an n-cube.
   • Now do it for a 10x10x10 where I only paint the top and bottom.

   Reported by candidates at TD Securities (Generalist, New York, 2024). Source: Wall Street Oasis.

5. 094How many aeroplanes are in the air at once?BrainteasersIntermediatetechnicalSTSociété GénéraleMergers and Acquisitions · New York · 2025HSBCSales and Trading · Hong Kong · 2026

   Say this

   Around ten to fifteen thousand. Build it from the fleet: roughly 25,000 commercial aircraft worldwide, each flying maybe 10 hours a day, so about 40 percent are airborne at any moment, which gives 10,000.

   Then walk it

   1. Start from a number you can defend: the global commercial fleet is on the order of 25,000 aircraft. If you do not know it, build it from airlines: a few hundred carriers averaging perhaps 80 aircraft.
   2. Utilisation: a commercial jet flies roughly 8 to 12 hours a day. Call it 10, which is about 40 percent of a 24-hour day.
   3. 25,000 times 0.4 gives 10,000 airborne on average.
   4. Then adjust for the peak-trough pattern. Air traffic is concentrated in daylight hours across the Northern Hemisphere, so the daytime peak might be 50 percent above average and the small hours well below. Peak perhaps 15,000.
   5. Then say what you excluded and why: private aviation, cargo and military would add to it, probably a few thousand more, and I have not counted them.
   6. Close with the sanity check: published flight-tracking figures sit in the same range, low to mid five figures, so the estimate holds.

   Where candidates lose it

   Guessing a number with no derivation, or getting lost in decimals. Market sizing is judged entirely on structure. State each assumption, keep the arithmetic round, and say which populations you left out.

   Expect next

   • How many taxis are in Hong Kong Central?
   • How many hotel beds are there in New York City?
   • How many books were sold in the US last year?

   Reported by candidates at Société Générale (Mergers and Acquisitions, New York, 2025); HSBC (Sales and Trading, Hong Kong, 2026). Source: Wall Street Oasis.

6. 095What is 301 times 447?BrainteasersIntermediatetechnicalGeneral AtlanticGeneralist · New York · 2026

   Say this

   134,547. Break 301 into 300 plus 1. Three hundred times 447 is 134,100, plus one more 447 gives 134,547.

   Then walk it

   1. Decompose to the nearest round number. 301 is 300 plus 1, and 300 is easy because it is 3 times 100.
   2. 447 times 3 is 1,341. Times 100 is 134,100.
   3. Add the remaining 447: 134,547.
   4. Announce the decomposition before you compute, so the interviewer can follow and so a slip in arithmetic does not look like a failure of method.
   5. The same trick handles most of these: round one number, multiply, then correct. For 19 times 63, do 20 times 63 minus 63.

   Where candidates lose it

   Attempting long multiplication in your head and losing a digit. These are speed-and-method tests. Decompose out loud, keep one running total, and offer the sanity check that the answer should be a bit over 134,000.

   Expect next

   • What is 19 times 63?
   • What is 1/7 as a decimal?
   • What is the square root of 6,241?

   Reported by candidates at General Atlantic (Generalist, New York, 2026). Source: Wall Street Oasis.

7. 097What do analysts actually do day to day, beyond financial modelling?FitIntermediatetechnicalRothschild & CoInvestment Banking · Exeter · 2026

   Say this

   Most of it is not modelling. It is building and formatting pitch materials, running diligence and data rooms, coordinating between lawyers, accountants and the client, and doing the unglamorous version control that keeps a live process from falling over.

   Then walk it

   1. Materials: pitchbooks, management presentations, information memoranda, board decks. Formatting to house standard, and endless turns of comments from three levels of seniority.
   2. Research and diligence: comps and precedent screens, industry reads, buyer lists, and managing the data room and the question log on a live deal.
   3. Process management: scheduling, tracking who has signed which NDA, chasing the lawyers and accountants, and keeping the working group list current. On a live deal this is most of the job.
   4. Then the modelling, which is the part everyone prepares for and probably a fifth of the time.
   5. And the part candidates never mention: quality control. Checking that every number in a 60-page deck ties to the model, and that the version being printed is the current one. That is where analysts actually get judged.
   6. Saying this clearly signals that you know what you are signing up for, which is exactly why the question gets asked.

   Where candidates lose it

   Describing the job as building models and advising CEOs. It is not, for the first two years, and an interviewer who does the job will hear the fantasy immediately. Naming the administrative reality without sounding unwilling to do it is the winning move.

   Expect next

   • Does that sound appealing to you?
   • How do you handle repetitive work?
   • Tell me about a time you fell behind schedule.

   Reported by candidates at Rothschild & Co (Investment Banking, Exeter, 2026). Source: Wall Street Oasis.

8. 099Tell me about a time you faced an ethical dilemma, or saw someone do something you thought was wrong.FitIntermediatesuperdayBank of AmericaInvestment Banking · New York · 2025J.P. MorganAsset Management · New York · 2026SSState StreetGlobal Data · Boston · 2024

   Say this

   Use a real, small, resolved example. Something where you noticed a problem, raised it through the right channel, and it was fixed. Scale does not matter; the pattern does.

   Then walk it

   1. Pick something genuinely ambiguous but low-stakes: a teammate misrepresenting data in a group project, an internship colleague using an outdated figure in a client-facing document, an expenses issue on a society committee.
   2. Structure it as situation, what made it a dilemma, what you actually did, and the outcome. Fifteen seconds on the setup, most of the time on the action.
   3. Show that you went to the person first before escalating. Interviewers in regulated firms want to see proportionality, not someone who immediately reports a colleague.
   4. Be specific about the discomfort. 'I did not want to accuse him, so I asked him where the number came from' is credible. Certainty is not.
   5. Avoid two failure modes: a story where you did nothing, and a story so grave that it raises questions about the environments you have been in. And never name a real employer's confidential matter, because how you handle that in the interview is itself the test.

   Where candidates lose it

   Claiming you have never faced one. That reads as either no self-awareness or no willingness to engage. Equally bad is a story where you stayed silent and rationalised it. Have one prepared, rehearsed, and resolved.

   Expect next

   • What would you have done if raising it had cost you the grade or the offer?
   • Tell me about a time you made a difficult decision.
   • Tell me about a time you disagreed with a manager.

   Reported by candidates at Bank of America (Investment Banking, New York, 2025); J.P. Morgan (Asset Management, New York, 2026); State Street (Global Data, Boston, 2024). Source: Wall Street Oasis.

Firm tags come from public, anonymous candidate reports on Wall Street Oasis: strong signal, not sworn testimony. Firms are named as the places a question was reported, not as partners of Fin Maverick. Answers are written for this page to show how to think out loud; they are not scripts to recite.