Quantitative Trader
Jane Street · Entry-level
Prepare for the Jane Street Quantitative Trader interview with 2 practice rounds and what each one looks for. Pick any round and an AI interviewer runs it with you at full length, with follow-up questions. Afterwards you’ll see what went well and what to work on next.
Your first 60 minutes of practice are free. No card needed.
Next: your first full round
Do the Phone interview: probability and reasoning round.
One full practice round shows where you stand before you work on anything specific.
The rounds
Pick a round to see what it asks of you and where you stand on it.
Phone interview: probability and reasoning
See whether you can solve probability and expected-value problems methodically, talk through your reasoning, check that your answer makes sense, and recover calmly from mistakes.
Engineering judgment · 45 minSet up this round
Not tried yetNo attempt yet.
What strong sounds like
- States a plan, defines events, and solves in ordered steps without jumping to a guessed answer.
- Explains each step as it happens, so the interviewer can follow and help at any point.
- Tests the result with a limit case or rough estimate. Corrects own errors without being asked.
Expect to be pushed on
Change a game rule and ask how the answer shifts.
Shapes of problem you may get
- Classic coin, dice or card probability puzzle with a twist
- Expected value of a simple game with a stopping choice
- Estimation problem that needs a sanity check and a range you'd stand behind
How to prepare
What they look for
Jane Street says its trading interviews start with phone interviews and end with in-person interviews. The final stage can cover problem solving, probability and statistics, coding in any language, data analysis and general interests, and Jane Street says it should feel more like a conversation than a quiz. Candidates report probability puzzles on the calls and dice, card and market-making games in person. The number and length of interviews aren't published, so this plan practices one phone interview and one in-person game interview.
They reward
- Reasoning you share as you go, not only the right answer
- Quick recovery when you find your own mistake
- Knowing how sure you are, and saying so
- Working with the interviewer on hard problems
What to avoid
- Don't give a final number without showing how you got there.
- Don't hide or defend a mistake once you spot it.
- Don't quote a price without a fair value behind it.
- Don't ignore what the other side's trade tells you.
How sure we are
Worth redoing if you hear something from the recruiter that contradicts this.
Attempts
Every round you’ve done for this job, newest first.
Phone interview: probability and reasoning and In-person trading games have no attempts yet.