Jane Street

You bet with a crowd on one of two horses, and everyone else always backs whichever horse has more past wins. How do you bet?

First round, technical. eFinancialCareers, Dec 18, 2025

A deck has 20 cards: 19 red and 1 black. You draw one at a time, earning $1 per red, and you may stop whenever you like, but drawing the black ends the game with nothing. How do you play and what is your expected payout?

First round, technical. eFinancialCareers, Dec 18, 2025

What are the odds that I, your interviewer, am related to a professional baseball player?

First round, technical. eFinancialCareers, Dec 18, 2025

How many fair coin flips do you expect to need to see three heads in a row?

First round, technical. Jane Street

Given that a fair die roll is prime, what is its expected value, and what is the chance it is 3 or less?

First round, technical. Jane Street

Give a 95% confidence interval for the number of taxis in New York City.

First round, technical. Jane Street

What is the probability that the product of two rolls of a fair die is odd? What about three rolls?

First round, technical. Jane Street

Make a market on the maximum of three rolls of a six-sided die.

First round, markets. Jane Street

Make a market on one roll of a six-sided die where the holder may reroll once. Does it matter who decides whether to reroll?

First round, markets. Jane Street

Make a market on 1,000,000 times one roll of a six-sided die. How would you feel if I hit your bid and it rolled a 1?

First round, markets. Jane Street

Why does trading interest you?

First round, behavioral. eFinancialCareers, Mar 16, 2026

What do you do for fun?

First round, behavioral. eFinancialCareers, Mar 16, 2026