Quantitative trading and research interviews look intimidating, but they test a surprisingly small set of skills — probability, expected value, fast mental arithmetic, and clear reasoning under pressure. This guide breaks down what to study, how the major firms differ, and how to practise so it actually sticks.
What quant interviews actually test
Almost everything reduces to a handful of areas:
- Probability — counting, conditional probability, distributions, and expectation, usually dressed up as dice, coins, cards, or betting games.
- Expected value — pricing bets and games, and deciding whether a wager is worth taking.
- Conditional probability and Bayes' rule — updating beliefs as information arrives; where most candidates slip.
- Mental math — fast, no-calculator arithmetic, especially at speed-focused shops.
- Market-making and betting games — quoting a two-sided price and managing risk and adverse selection.
- Brainteasers, statistics, and — for research and developer roles — programming.
Key insight. You don't need a finance background for most trading roles — Jane Street, for one, explicitly doesn't test it. Interviewers care about how you reason far more than what jargon you know.
How the major firms differ
The emphasis shifts by firm, so tailor your prep:
| Firm type | Examples | What to expect |
|---|---|---|
| Speed shops | Optiver, Flow Traders, IMC | Timed mental-math / numerical filters first |
| Game & EV shops | Jane Street, SIG | Probability, EV, betting and market-making games |
| Research & engineering | Citadel, Two Sigma, DRW | Deeper stats + coding, via technical assessments |
| Options market makers | Akuna Capital | Options & market-making intuition + mental math |
Browse the full list of firms to see which topics each one emphasises.
A four-week study plan
- Week 1 — foundations. Drill probability and expected value until the common setups are automatic. Review the worked solution to every problem you miss.
- Week 2 — speed and conditioning. Build mental-math speed with the Mental Math simulator (see the speed mental-math guide), and work conditional probability problems.
- Week 3 — trading judgement. Practise market-making and betting games — the Make a Market and Take the Bet games train quoting and EV decisions under pressure.
- Week 4 — firm-specific. Pick your target firm's guide and track, and run the timed Probability OA to simulate the real assessment.
How to practise so it sticks
The single most important habit. Volume with feedback beats re-reading theory. Attempt a problem, check your answer, and study the solution whenever you're wrong — that loop is where learning actually happens.
- Practise under mild time pressure. Interviews are timed; your practice should be too.
- Think out loud. At firms like Jane Street and SIG, the method is graded as much as the answer.
- Target your weak topics. If conditioning or counting keeps tripping you up, drill that specific area rather than grinding what you already know.
Ready to start? Create a free account to practise hundreds of questions with hints and answer checking, or browse questions by firm and topic.