Jane Street · Quant trader / software engineer · Quant Trader, new grad / intern
Market-Making Game (spoken)
The signature Jane Street round
What they actually ask
The question shapes this round uses. Larpy does not read these out. It builds each one from your own resume, because the generic version is the one you have already rehearsed.
- “Make me a market on the outcome of a 20-sided die.”
- “Make me a market on the maximum of three six-sided dice rolls.”
- “Make a market on a die where you're allowed one reroll, who decides to reroll, and does that change your price?”
- “Make a market on the temperature one hour from now.”
- “Make a market on one million times the outcome of a six-sided die. How would you feel if I hit your bid and it rolls a 1?”
What this round is judged on
- Expected-value reasoning · price around a sensible EV
- Spread-setting · widen where uncertain, tighten where known
- Adverse selection · re-price after each fill given who traded with you
- Risk sizing · size to survive bad outcomes
- Updating on information · revise your market as new info arrives
Where this round sits
Jane Street’s published process. Lime marks the stage this round runs.
- 01Application
- 02Phone interviews (remote)
- 03In-person final round (onsite)this round
- 04Decision
What happens in each stage›
- Application
- Rolling basis, no deadline. No GPA or degree requirement; interns come from 70+ universities. Jane Street says you can expect to hear from a recruiter within a few days.
- Phone interviews (remote)
- One or more remote interviews to start. For trading these are conversational probability/logic and market conversations with an actual quant trader; for SWE they are live coding. The interviewer calls you (Zoom if connectivity is poor).
- In-person final round (onsite)
- The final stage is in person: multiple back-to-back interviews mixing probability, a market-making game, estimation, a light coding/data-analysis chat, and fit. Jane Street books and pays for travel and hotel; interviews run weekdays only, dress casual.
- Decision
- Jane Street says you should hear back within about a week after the final stage. Reapplication is explicitly allowed (recommended wait ~1 year).
Sources
Built from what Jane Street publishes about its own process and from real interview data. No leaked question lists. The questions you get are generated against your own resume, so they are not from anyone else's interview.
Two-stage process, conversation-not-a-quiz philosophy, any-language coding and OCaml guidance, logistics and reapplication
Trading two-stage structure, final-round content, desired traits, four principles, myth-busting on mental math and theorems
Trading interview syllabus, verbatim example probability/EV questions, market-making game prompts and quoting jargon, adverse selection
Company blurb, roles, 'smart people with curious minds from any background'
Official software-engineering mock interview walkthrough referenced by the interviewing page
Confirms Jane Street SWE levels (L1-L4) and titles including Quantitative Developer and Full-Stack Software Engineer
Sources last checked . Hiring loops change, so this date is the honest limit on everything above.
Other Jane Street rounds
- Recruiter Screen
Light, warm, conversational
- Fit / Why Jane Street
Low-key and genuine, not a McKinsey-style structured behavioral
- Probability & Expected Value (spoken)
Run by an actual quant trader
- Estimation & Problem Solving (spoken)
Fermi/estimation and open reasoning, plus a light data-analysis and general-interests chat
- Coding Phone Screen
Collaborative, discussion-heavy live coding in your own language and setup
- Onsite Coding
Harder onsite live coding, same collaboration-over-a-right-answer ethos