Jane Street

Interview Question

Trading Intern Interview
Jane Street

We're going to play a game. You go first. You flip a coin; if you get heads, I give you $30. If you get tails, you give me the coin and I flip. If I get heads, you give me $30; if I get tails, I give it back to you. We keep going until one of us gets heads. What is the maximum amount you would be willing to pay to go first? Give a 50% confidence range and a 90% one for your answer. Why?

Unlock the Full Solution

Enter your email to get instant access to the complete solution, explanation, and similar practice problems.

Insights on 100+ quant firms, understand where to apply, and maximize your chances.

Get the official 2025 QB Quant Firm Tier List

Check your email inbox — you should get the interview in 1-2 minutes!