The Green Book for Quant Interviews: What It Covers and How to Use It

What the Green Book (A Practical Guide to Quantitative Finance Interviews) covers, how to use it for daily interview prep, whether it is enough, and the other books quant candidates use.

The Green Book is A Practical Guide to Quantitative Finance Interviews by Xinfeng Zhou, a book that analyzes solutions to more than 200 real interview problems in brain teasers, calculus, linear algebra, probability, stochastic calculus, finance and programming. I think it is the top resource for quant technical interview prep, so yes, use it. Work through it every day and out loud, alongside coding practice and mental math, because no single book covers everything firms test.

I'm Fiona Taft, founder of QuantMinds, former Executive Director of UC Berkeley's MFE program and former Associate Director at Stanford University. The guidance here is drawn from my recorded webinars on quant recruiting. Quotes from my webinars are lightly edited for clarity, and book details come from publisher, author, bookseller and library catalog pages.

What is the Green Book?

"The Green Book" is the nickname for A Practical Guide to Quantitative Finance Interviews, written by Xinfeng Zhou. The 2020 printing was published on May 5, 2020, with ISBN 9781735028804, and its publisher is listed as the author, Xinfeng Zhou. Google Books and Amazon list it at 210 pages; Goodreads lists 209. Earlier printings date back to 2008, through Lulu and CreateSpace.

The catalog pages behind this article do not give a reliable edition number for the 2020 printing. When you buy or borrow a copy, look for the 2020 date or the ISBN above so you know which printing you have.

The book's description says it analyzes solutions to more than 200 real interview problems. That is the core of why I point candidates to it. In my webinar What you need to do now to land a 2027 internship, I said: "I think the top resource is going to be the Green Book. If you don't know what the Green Book is, then you very much should. This is a book that has so many questions for prepping you in different areas, from math, to probability, to statistics, to brain teasers, to some of the technical questions."

What the Green Book covers

The book's description lists these areas:

Brain teasers
Calculus
Linear algebra
Probability
Stochastic processes and stochastic calculus
Finance
Programming

Those areas line up with the technical side of quant recruiting: the online assessment, a timed technical test that many firms run on HackerRank, and the live technical interviews that follow it. If calculus, probability, stochastic processes or linear algebra feel rusty, read the math you actually need to break into quant finance before you start, so the problems test your reasoning rather than your memory of a formula.

Two things are missing from that topic list. Behavioral interviews are not on it, and neither is the timed mental math that many assessments include. Both need their own practice, which I cover below.

How I recommend using the Green Book

My core advice is daily practice. In my webinar What You Need to Do NOW to Land a 2027 Summer Quant Internship, I put it this way: "You should be doing daily assessments in quick math, you should be doing daily assessments in brain teasers, you should do daily assessments in probabilities, statistics, and various other models. If you have not heard of the Green Book, the Green Book is a great way to be prepping for your technical interviews."

In my Quant Finance Career AMA, I made the same point: "You also should be doing daily practice on your technicals, whether that's in the Green Book, whether that's on [a mental math practice site]."

Here is how to turn that into a routine:

Practice a little every day. Steady daily work beats cramming, and an online assessment can arrive with a deadline only days away. Start before your first one lands.
Try each problem before reading the solution. Work it on paper first, then compare your method with the book's. Learn the method, not the answer, because interviewers change the numbers.
Solve out loud. In a live interview, the interviewer can only credit reasoning they hear. State your assumptions, set up the problem, and estimate before you calculate, exactly as you would in the room.
Pair it with coding. Practice coding daily on LeetCode, and set up a free HackerRank account, since many firms use HackerRank for their assessments.
Keep mental math as its own block. Speed with arithmetic under time pressure is a separate skill, so practice it on a timer every day alongside the book.

Firms also ask about your study habits directly. In the same AMA, talking about a question that banks, hedge funds and prop trading firms ask in behavioral interviews, I said: "What do you do to keep on top of the markets? What do you read? What do you study? How do you keep on top of the latest strategies? So think about that. Are you reading the Wall Street Journal every day? Are you practicing the Green Book?" Daily Green Book practice is preparation for the technical rounds and part of a real answer to that question.

Is the Green Book enough?

No. It covers the math, probability and brain teaser side of quant interviews, but firms test more than that:

Coding. Daily practice on LeetCode, plus HackerRank for the assessment format. For quant developer roles, coding comes first.
Mental math. Fast, accurate arithmetic under time pressure, practiced on a timer.
Behavioral preparation. Your resume, your projects and why you want this firm, rehearsed out loud with another person.
Market making. For market-making firms, I tell candidates to study poker and market making too.
Firm research. Why this firm, why this team, and why you, for every firm on your list.

For original practice questions with worked answers across probability, statistics, brain teasers, mental math, market making, coding and behavioral rounds, see our guide to quant interview questions. For where interviews sit in the full hiring process, from the resume screen to the final round, read how to become a quant.

Other quant interview books candidates use

I have not covered the books below in my webinars, so this section is not a recommendation from me. Each description comes from the book's own catalog, publisher or author pages, and they are listed in no particular order.

Heard on the Street (Timothy Falcon Crack)

Heard on The Street: Quantitative Questions from Wall Street Job Interviews is by Timothy Falcon Crack, and the publisher listed is the author. The 27th edition, published on September 3, 2026, runs 424 pages. Its description says it contains 247 quantitative questions collected from actual job interviews in investment banking, investment management and options trading, covering pure quant and logic, financial economics, derivatives and statistics. It also includes 278 non-quantitative interview questions and a revised section on interview technique.

Quant Job Interview Questions and Answers (Joshi, Denson and Downes)

Quant Job Interview Questions and Answers is by Mark Joshi, Nicholas Denson and Andrew Downes, published by Pilot Whale Press. The second edition came out in 2013 at 375 pages, after a first edition in 2008. Its description says it has over 300 questions taken from actual interviews in the City (London's financial district) and on Wall Street, covering option pricing, probability, mathematics, numerical algorithms and C++, plus the interview process and the non-technical interview. Each question comes with a full solution, a discussion of what the interviewer is looking for and possible follow-up questions.

Fifty Challenging Problems in Probability (Frederick Mosteller)

Fifty Challenging Problems in Probability with Solutions is by Frederick Mosteller. It was first published in 1965, and Dover Publications reprinted it in 1987. Its description presents it as a selection of puzzlers, graded in difficulty, that illustrate both elementary and advanced aspects of probability, with detailed solutions. It is short, at 88 pages according to Google Books, and its scope is probability alone rather than interviews as a whole.

Cracking the Coding Interview (Gayle Laakmann McDowell)

Cracking the Coding Interview: 189 Programming Questions and Solutions is by Gayle Laakmann McDowell, published by CareerCup. The 6th edition came out in 2015. It is a programming interview book: alongside 189 programming questions with solutions, in categories such as arrays and strings, trees and graphs, math and logic puzzles, and recursion and dynamic programming, it covers the interview process, behavioral preparation, Big O (how an algorithm's running time and memory grow with the size of its input) and the offer stage. Its behind-the-scenes section covers interviews at Microsoft, Amazon, Google, Apple, Facebook and Palantir, and the author's site says the solutions are written almost entirely in Java.

Which book to start with

Start from the role you are targeting. If you have not picked one yet, read QR, QT or QD: which quant path is right for you.

Quant research or quant trading: start with the Green Book. It is the book I point candidates to in my webinars, and its topics match the math, probability and brain teaser side of the assessment and the technical rounds.
Quant development: coding comes first in those interviews, so put a coding interview book or daily LeetCode practice ahead of, or alongside, the Green Book.

If you add a second book, choose by the gap you need to fill, using each book's stated coverage above: for example, derivatives and non-quantitative questions, option pricing and C++, or probability on its own.

Frequently asked questions

What is the Green Book in quant finance?

It is the nickname for A Practical Guide to Quantitative Finance Interviews by Xinfeng Zhou. Its description says it analyzes solutions to more than 200 real interview problems in brain teasers, calculus, linear algebra, probability, stochastic calculus, finance and programming. I name it the top resource for quant technical interview prep.

Is the Green Book enough to pass quant interviews?

No. Pair it with daily coding on LeetCode, a HackerRank account for the assessment format, timed mental math, behavioral answers practiced out loud and research on each firm. If you are applying to market-making firms, study market making too.

Green Book vs Heard on the Street: which first?

Start with the Green Book; it is the one I recommend in my webinars. Heard on the Street is another book candidates use. The description of its 27th edition lists 247 quantitative interview questions, 278 non-quantitative questions and a section on interview technique, so consider it if those areas match a gap in your preparation.

Is there a free PDF of the Green Book?

We do not link to unofficial copies. Buy the book from a retailer, or borrow it through your university library. Searching by the 2020 printing's ISBN, 9781735028804, helps you find that printing.

How long does it take to work through the Green Book?

I don't set a timeline for it. What I recommend is daily practice, started before your first online assessment arrives and kept up through recruiting season.

What other books do quant candidates use for interviews?

Heard on the Street by Timothy Falcon Crack, Quant Job Interview Questions and Answers by Mark Joshi, Nicholas Denson and Andrew Downes, Fifty Challenging Problems in Probability with Solutions by Frederick Mosteller and, for coding, Cracking the Coding Interview by Gayle Laakmann McDowell. I have not covered these in my webinars; the descriptions above come from their catalog, publisher and author pages.

Get a second opinion

If you want a second opinion on your interview prep, you can request a free Discovery Session, a Zoom session with one of our coaches: quantminds.com/discovery-session-request.