The Woo on Jane Street interviews

Jane Street interviews are math-heavy and fast. Expect probability, mental arithmetic, and brainteasers — often simultaneously.

What to expect

• 3-5 rounds, mostly 1-on-1.
• Mental arithmetic: 47 × 23, square roots, etc. Practice.
• Probability: coin-flip games, expected value, conditional probability.
• Estimation: "how many piano tuners in NYC?"
• Markets: basic options, futures, intuition about pricing.

How to prepare

• Green book (this site).
• Mental math practice (Zetamac, etc.).
• Read Options, Futures, and Other Derivatives (Hull) for the markets questions.

Don't fake it. If you don't know something, say so — they value honesty over bluffing.