Jane Street’s Trading Interview: What to Expect

SUMMARY

In 30 seconds

Jane Street trader Michael and recruiter Megan describe a process that emphasizes quantitative reasoning, communication, teachability and carefulness rather than prior finance knowledge. They recommend thinking aloud, checking answers and breaking difficult questions into manageable cases, while addressing misconceptions about mental math and mistakes.

1Foundational skillsThe process considers quantitative thinking, communication, teachability and carefulness.
2Interview stagesThe speakers describe two or three phone interviews followed by up to a day of in-person or virtual interviews.
3Think out loudExplain your reasoning and take time to check your answer; accuracy matters more than speed.
4Start with a workable strategyFor open-ended games, make assumptions and improve a first approach by considering how it could be exploited.
5Mistakes are part of problem-solvingInterviewers consider how candidates work through difficult questions, not just whether they are immediately correct.

Takeaways

The described interviews assess quantitative thinking alongside communication, carefulness and teachability.
The speakers say prior finance knowledge and advanced mathematics are not required.
Thinking aloud gives the interviewer insight into the reasoning, including when a question has no single answer.
Simplifying assumptions, smaller cases and working backward can make an open-ended problem manageable.
A mistake does not automatically mean failure, and reinterviewing is considered case by case.

TopicsCareers Hiring

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Purpose and interview structure

Michael and Megan introduce the foundational skills assessed and describe the phone and final interview stages. They say prior finance knowledge and advanced mathematics are not required.

Michael, a trader who joined Jane Street in 2018, and Megan, a trading recruiter who joined in 2008, explain the purpose and structure of the firm’s trading interviews. They also discuss common misconceptions about what candidates need to know and how they are evaluated.

The process tests foundational trading skills, including quantitative thinking, communication, teachability and carefulness. The speakers say the questions require neither prior finance knowledge nor advanced university mathematics. Even complicated scenarios can be analyzed without especially high-level techniques; intuition for probability and expected value is particularly useful.

The process begins with two or three phone interviews and may lead to up to a day of interviews in person or over Zoom. Traders conduct the interviews. Candidates may use pen and paper but are asked not to use a computer or calculator.

Reasoning together

Candidates are encouraged to think aloud and prioritize accuracy. Later questions can be open-ended and invite a collaborative discussion.

The speakers strongly encourage candidates to think out loud. Interviewers want to understand the reasoning, not simply whether the final answer is right; some questions may not have one right answer. Speed is useful, but accuracy matters more, and candidates can take time to check whether an answer makes sense.

Early interviews generally use simpler problem-solving techniques and basic probability. Later questions become more complex and open-ended. The intended experience is a conversation about an interesting problem, closer to working together on a trading desk than taking a test.

For instance, a question might involve playing a game against someone whose actions cannot be predicted. Finding an optimal strategy may be very hard, so a candidate can make assumptions, propose a reasonable first strategy and then look for ways an opponent could exploit it.

A useful general approach is to reduce an unsolved problem to one you can solve. The speakers suggest simplifying assumptions, trying smaller cases and working backward. These steps provide a starting point for refining an answer together.

Common misconceptions

The speakers address mental arithmetic, mistakes during an interview and the possibility of interviewing again. They emphasize numeracy and a range of interpersonal and problem-solving qualities.

One misconception is that success requires extraordinary mental arithmetic. The speakers say they do not care whether a candidate can quickly multiply 37.2 by 93. They do value numeracy: for example, intuitively recognizing that the average of numbers from 1 to 1,000 is roughly 500, or that squaring a number between zero and one makes it smaller.

Another misconception is that one wrong statement automatically means failure. The questions can be difficult, and interviewers are interested in how candidate and interviewer work together on a hard problem. They consider communication, intuition, tenacity and teachability as well as quantitative ability.

Finally, not making it through the process one year does not automatically prevent a later interview. Decisions are made case by case, and the speakers say some Jane Street traders—including one of them—did not succeed on their first attempt. They point candidates to a mock interview and a probability and markets guide for further preparation.