Investment Banking interview preparation
Every question below is either traced to a named firm from a public candidate report, or tagged at desk level when we could not trace it. Answers are written the way you would actually say them out loud — answer first, then the mechanism, then the limitation.
100 questions, mapped to the firms that asked them
- Questions
- 100
- Traced to a firm
- 100
- Firms
- 46
- Updated
- September 2026
018What is WACC and how do you calculate it?CitiGeneralist · New York · 2026
Say this
It is the blended after-tax cost of a company's capital, weighted by the market value of each piece. Cost of equity times the equity weight, plus after-tax cost of debt times the debt weight.
Then walk it
- Cost of equity comes from CAPM: risk-free rate plus beta times the equity risk premium, with a size or country premium if the situation calls for it.
- Cost of debt is the yield the company would pay on new debt today, not the coupon on its old debt, and you multiply it by one minus the tax rate because interest is deductible.
- Weights use market values, not book. Market capitalisation for equity, and market value of debt, which for most investment grade paper is close enough to book.
- Use target capital structure rather than today's snapshot if today's is temporarily distorted.
- The honest caveat is beta. It is estimated from noisy historical data, so I would cross-check against a peer set rather than trusting one regression.
Where candidates lose it
Using the coupon on existing debt as the cost of debt, or using book equity in the weights. Both are common and both are wrong. WACC is forward-looking and market-based.
Expect next
- Why do you unlever and relever beta?
- Can debt ever be more expensive than equity?
- What happens to WACC as you add leverage?
Reported by candidates at Citi (Generalist, New York, 2026). Source: Wall Street Oasis.
096Why investment banking, and why this firm?Goldman SachsInvestment Banking · New York · 2026CitiInvestment Banking · San Francisco · 2025Truist SecuritiesInvestment Banking · Charlotte · 2026Deutsche BankInvestment Banking · London · 2022Rothschild & CoInvestment Banking · London · 2025
Say this
Three beats: a specific moment that got you interested, what you did to test that interest, and one concrete reason for this firm that could not be copy-pasted to a competitor.
Then walk it
- The origin has to be specific and true. A deal you followed, a project where you built a model, a company in your family, a case competition. Not 'I have always been passionate about finance'.
- Then the evidence that you tested it, because interest is cheap and action is not. A society, a self-taught model, an internship, a stock you have tracked for two years.
- Then why banking rather than the adjacent options, and be honest about the trade you are making. Something like: I want the transaction seat rather than the research seat because I want to be inside the execution, and I know what the hours cost.
- Then why this firm, with one fact that is true only of them: a specific deal, a sector franchise, the size of the analyst class, the staffing model. One real fact beats three generic compliments.
- Keep it to about ninety seconds and finish cleanly instead of trailing off. Then stop talking.
Where candidates lose it
A 'why this firm' answer that would work for any of their competitors. Interviewers hear forty versions a day and the generic ones blur. Name one thing only they do, and if you have spoken to someone there, say who and what they told you.
Expect next
- Why you over the other candidates from your university with the same experience?
- What do you think analysts actually do day to day?
- Which group do you want and why?
Reported by candidates at Goldman Sachs (Investment Banking, New York, 2026); Citi (Investment Banking, San Francisco, 2025); Truist Securities (Investment Banking, Charlotte, 2026); Deutsche Bank (Investment Banking, London, 2022); Rothschild & Co (Investment Banking, London, 2025). 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.