EX-BANKERS EXPLAIN: Investment Banking Mistakes To AVOID In Your First Year

Why It Matters

Clear, repeatable habits around accuracy, prioritization and speed determine whether junior bankers add value or create costly errors; cultivating those skills early reduces firm risk and accelerates career progression.

Summary

Two veteran bankers share practical advice for first-year investment bankers and summer interns, stressing that finance is not about raw intellect but disciplined execution: get work done quickly, accurately and efficiently. They emphasize obsessive attention to detail—especially on external materials and valuations—because small errors can have outsized consequences on big deals and reputations. New hires should prioritize tasks by importance to avoid burnout, learn to check work repeatedly, and adapt to modern tools like AI while remaining vigilant for mistakes. The speakers draw on early-career mishaps to illustrate that early errors are common but avoidable with good habits and mentorship.

Original Description

Starting your first year in investment banking, equity research, private equity, or private credit?

Two senior practitioners share the mistakes they made, the ones they watched others make, and the unglamorous habits that separate the analysts who make it from the ones who don't.In this episode of What's the Big Deal?, Debs and Graham step away from the deal-of-the-week format for a candid conversation aimed at the next wave of summer analysts and first-year hires.

From Lehman Brothers in 2005 to Aries Management today, they cover what actually matters in your first year, what doesn't, and how to recover when you inevitably get something wrong.

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Timetstamps:

00:00 — Cold open: when you screw up, and you will screw up

00:33 — This week's topic: lessons for new starters in finance

03:09 — Graham's biggest mistake at Lehman Brothers

08:01 — Attention to detail in the age of AI

08:35 — Debs's career-limiting moment in equity research

10:45 — Why trust takes so long to rebuild

11:13 — The net debt error that should have ended a career (and didn't)

13:05 — Owning mistakes: recoverable vs. career-limiting

17:30 — Take every learning opportunity you can get

18:42 — How to ask questions that add value

20:07 — Why prep is the easiest way to stand out

21:15 — Boardroom exposure: don't waste it

22:19 — Standing out when the class is too big to be noticed

24:13 — Why sharp elbows are the wrong instinct

25:20 — Top survival tips: physical sanity, availability, sleep, calendar

29:08 — Follow your gut, ask for help, be a team player

30:44 — Closing thoughts

Topics covered:

→ Graham's biggest screw-up at Lehman Brothers (and what his VP said)

→ Debs's near-career-limiting moment in equity research

→ Why finance math isn't the hard part of the job

→ Attention to detail and what AI changes (and doesn't)

→ The difference between recoverable mistakes and career-limiting ones

→ Why sharp elbows are the wrong instinct

→ How to ask questions that add value

→ Boardroom exposure: don't waste it

→ Prep, calendars, sleep, and the unglamorous habits that actually matter

→ Why being a team player matters more than being the smartest in the roomWhether you're starting a summer analyst program, a full-time analyst role, or moving into a buy-side seat for the first time, this is the episode for you.

Why Wall Street Prep?

Wall Street Prep is the trusted training provider for the world's top investment banks, private equity firms, Fortune 1000 companies and business schools. Our online training and instructor-led boot camps are direct adaptations of our corporate training, making Wall Street Prep the ideal choice for those looking to break into finance.

DISCLAIMER:

The information provided in this video is for educational and entertainment purposes only and does not constitute financial, investment, tax, or legal advice. Investing involves risk, and you may lose some or all of your capital. Past performance is not indicative of future results. Please conduct your own due diligence or consult with a certified professional before making any financial decisions.