Master Quant Interviews.
Structured practice for quantitative trading, research and developer interviews. Probability to stochastic calculus, option pricing to market making, each problem with progressive hints and a full worked solution.
- problems
- 118
- topics
- 15
- lessons
- 6
- real interview questions
- 80
Positive Test, Rare Condition
A condition affects 1% of a population. A screening test has a 99% true-positive rate (sensitivity) and a 5% false-positive rate. A randomly selected person tests positive.
What is the probability that they actually have the condition?
Coverage
Every topic the interview loop actually tests
From the brain teaser in the first phone screen to the stochastic calculus in the final round.
Probability & Combinatorics
Conditioning, counting, symmetry and the classic puzzles every desk asks.
34 problems
Statistics & Statistical Inference
Estimators, hypothesis tests and regression, the way researchers use them.
13 problems
Expected Value & Decision Theory
Linearity of expectation, optimal stopping and bet sizing.
22 problems
Brain Teasers & Logic
Structured reasoning under pressure: induction, invariants, backward reasoning.
8 problems
Mental Math & Estimation
Fast arithmetic and sanity-checkable approximations.
3 problems
Market Making & Trading Games
Fair value, quoting, adverse selection and inventory under uncertainty.
5 problems
Stochastic Processes & Markov Chains
Random walks, absorption, stationary distributions.
6 problems
Stochastic Calculus
Brownian motion, martingales and Itô's lemma.
6 problems
Derivatives Pricing & Greeks
No-arbitrage, Black–Scholes and the sensitivities traders hedge.
5 problems
Fixed Income & Interest Rate Models
Discounting, yields, duration and forward rates.
3 problems
Linear Algebra & Optimization
Covariance matrices, eigen-structure and portfolio optimisation.
3 problems
Machine Learning & Time Series
Autoregressive models, overfitting and backtest hygiene.
2 problems
Algorithms & Data Structures
Efficient algorithms on price series and streams.
3 problems
Python / C++ Quant Coding
Implementing quant building blocks cleanly and correctly.
2 problems
Numerical Methods & Monte Carlo
Simulation, error estimates, root finding and variance reduction.
3 problems
Featured
Problems worth your time
A cross-section of the bank, from classic puzzles to production-style code.
Expected Flips Until HTH
Probability & Combinatorics
coin flips · patterns · first-step analysis
Make a Market: Three Dice
Market Making & Trading Games
market making · fair value · adverse selection
Implied Volatility by Bisection
Derivatives Pricing & Greeks
implied volatility · root finding · black-scholes
Gambler's Ruin with an Edge
Stochastic Processes & Markov Chains
random walk · gambler's ruin · absorbing states
Show W² − t Is a Martingale
Stochastic Calculus
martingales · brownian motion · proof
How Negative Can Three Correlations Be?
Linear Algebra & Optimization
correlation matrix · positive semidefinite · eigenvalues
Workspace
The right answer format for each kind of question
Not everything in a quant interview has a single number for an answer. LeetQuant grades what can be graded and is honest about what can't.
Multiple choice & numerical
Exact answers with fractions and expressions, or tolerance-graded estimates.
Mathematical free response
Write derivations in LaTeX with live preview, then self-assess against a rubric.
Python coding
Monaco editor and sample tests that run in your browser via WebAssembly.
Market-making simulation
Quote, manage inventory and get a transparent PnL decomposition.
Learning paths
Prepare for the seat you're interviewing for
Set a target role and your dashboard weights recommendations toward the topics that role is tested on.
Quant Trader
Fast probability, expected value under pressure, and making markets when you don't know the answer.
Quant Researcher
Statistical judgement, time series and stochastic calculus, with derivations you can defend.
Quant Developer
Clean, efficient implementations of the numerical building blocks a trading stack depends on.
Desk Quant
Pricing, Greeks, rates and the risk-neutral intuition you need on a derivatives desk.
Curriculum
Learn it properly, then prove it
Original lessons with worked examples and knowledge checks, each linked to problems that test the same idea.
Probability for Quant Interviews
- Conditional Probability & Bayes' Theorem
- Counting & Combinatorics
- Expected Value & Linearity
- Conditional Expectation
Statistics for Quant Researchers
- Estimation & Hypothesis Testing
- Regression
- The Bias–Variance Tradeoff
- Time-Series Analysis
Stochastic Calculus & Derivatives
- Brownian Motion & Martingales
- Itô's Lemma
- Risk-Neutral Pricing & Black–Scholes
- Greeks & Dynamic Hedging
Quantitative Trading
- Market Making: Fair Value, Spread & Adverse Selection
- Inventory Risk
- Optimal Betting & the Kelly Criterion
The expected value of practice is positive.
Start with a problem, or work through a course from the beginning.