Quant interview prep

Short answer: quant interview prep comes down to five trainable skills: fast, accurate arithmetic under a clock, probability and expected value, spotting patterns, estimating, and thinking in prices. R3CK0N's Quant Prep section practises each of them free in the browser, with a timed trading-test sprint, probability questions and a market-making game. None of it needs a paid course.

What gets tested

Formats differ by firm and change over time, so treat this as the general shape rather than a spec:

• Timed numerical tests. Many trading firms screen with a short online test: a long list of arithmetic questions (whole numbers, decimals, fractions, percentages, missing operands) against a clock too tight to finish comfortably. Some are multiple choice and penalise wrong answers, so guessing costs you.
• Probability and expected value. Dice, cards and coins; conditional probability; the expected value of a game and the best strategy for it. Often asked live, where explaining your reasoning matters as much as the answer.
• Sequences and estimation. Find the next term; estimate a quantity to the right order of magnitude without paper.
• Market making. "Make me a market on the sum of three dice": quote a price to buy and a price to sell, then update as information arrives.
• Brainteasers. Logic and counting puzzles that reward a clean method over a flash of insight.

Trader roles lean hardest on speed and markets; researcher roles on probability, statistics and depth; developer roles add programming. Everyone gets some arithmetic.

How to practise each part

• Trading sprint. A timed multiple-choice arithmetic test scored +1 for a right answer, −1 for a wrong one and 0 for a skip, so you learn when to skip. Its breakdown shows which kind of question costs you the most time. Quant Prep → Trading sprint.
• Interview questions. Original questions with worked solutions across probability, expected value, combinatorics, statistics and brainteasers, plus options and markets (payoffs, put–call parity, binomial pricing, the Greeks), linear algebra and calculus for research roles, and algorithms, complexity and code reading for developer roles. The generated ones never run out. Quant Prep → Interview questions.
• Mock phone interview. A short session of questions for your role: read, think aloud against the clock, answer, compare with the worked solution, then check yourself on whether you stated your approach, sanity-checked the answer and explained clearly. Quant Prep → Mock interview.
• Missed questions come back. A question you get wrong can become a flashcard in a "Missed questions" deck, scheduled with spaced repetition, so the method sticks instead of being seen once and forgotten. How spaced repetition works.
• Sequences and Estimation drills. Timed, in Math mode's Quant interview row. Estimation is scored by how close you get, within a factor.
• Market making. Quote a bid and an ask on dice, cards or coins as values are revealed; a counterparty trades against prices it thinks are wrong. Afterwards you see the fair value at every step and how far off your prices were. Quant Prep → Market making.
• Arithmetic foundations. Mental math for trading interviews, two-digit multiplication, fractions to decimals and percentages.

A six-week plan

Quant Prep's Plan tab has a live six-week track for traders, researchers and developers: every week has measurable targets (a sprint score, an accuracy on a topic, a number of mock interviews) that tick off automatically from your results, and it always shows what to do next. The trader track, in outline:

1. Baseline with a classic sprint, then daily arithmetic drills on your slowest operation.
2. Decimals, fractions and percentages until they are reflexes.
3. Sequences and estimation.
4. Probability and expected value, reviewing missed questions as flashcards.
5. Combinatorics, statistics and brainteasers, out loud.
6. Market-making rounds and full sprints under test conditions.

Short daily sessions beat occasional long ones. Keep one fixed sprint preset as your benchmark so you compare like with like.

Applying to a master's in financial engineering?

Admissions for quant finance programs lean heavily on the GRE Quant score. GRE Prep has practice in every GRE question format and timed sections, and the GRE prep guide covers what to know.

Frequently asked questions

Are these the real tests firms use?

No. Every question here is original and generated or written for practice. The formats are modelled on what candidates publicly describe, so the skills transfer, but no firm's actual test is reproduced.

Is it free?

Yes. No ads, no paywall, and no account needed. Signing in syncs your runs and flashcards across devices.