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Quantitative Researcher Interview Questions
Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.
- 9403
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- 546
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Showing 31–59 of 59 results
- Point72MediumQuantitative ResearcherEncode Categorical Variables Across Model Families
Choose categorical encodings for linear, tree, and neural models while handling intercept rank, unseen values, and high cardinality.
Machine LearningOnline Assessment - Point72MediumQuantitative ResearcherEstimate Factor Returns and Residual Returns
Derive weighted factor-return estimates from a sample, then compute residual returns across a larger trading universe with stable linear algebra.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherExplain Ensemble Learning and Its Main Families
Explain why combining multiple models can improve predictions. Cover data and labels, leakage-safe features, baselines and model choice, offline evaluation, deployment constraints, monitoring, and drift.
Machine LearningTechnical Screen - Point72MediumQuantitative ResearcherExplain Transformer Encoder and Decoder Behavior
This question evaluates knowledge of Transformer architecture and generative language modeling, specifically the encoder versus decoder roles, attention patterns and causal masking, plus mechanisms behind stochastic text generation such as sampling and temperature.
Machine LearningTechnical Screen - Point72MediumQuantitative ResearcherFind the Minimum in a Rotated Sorted Array
A strictly increasing array of distinct integers has been rotated at an unknown pivot. Work through the function contract, boundary cases, correctness argument, and time and space complexity expected in a production-quality solution.
Coding & AlgorithmsTechnical Screen - Point72HardQuantitative ResearcherFind the Two Heaviest Balls with Minimum Comparisons
There are 32 balls with distinct weights. Explain the assumptions and derivation clearly, check edge cases, and show how the result changes when those assumptions no longer hold.
Statistics & MathTechnical Screen - Point72MediumQuantitative ResearcherFormulate a Single-Period Stat-Arb Objective
Formulate a convex single-period statistical-arbitrage objective balancing expected return against covariance risk, with consistent units.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherLinearize an L1 Trading Penalty
Linearize weighted absolute trading costs with auxiliary variables, complete LP constraints, the correct objective sign, and an equivalence proof.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherModel Trading Frictions in Portfolio Optimization
Extend a stat-arb objective with unit-consistent commissions, spread, slippage, market impact, turnover, borrow, and concentration costs.
Statistics & MathOnline Assessment - Point72MediumQuantitative ResearcherProve That Lasso Can Be Written as a Quadratic Program
Derive the Lasso quadratic-program formulation and prove equivalence, convexity, minimizer correspondence, and rank-related uniqueness.
Statistics & MathTechnical Screen - Point72MediumQuantitative ResearcherSolve Three Probability Models
Solve three independent probability questions. Explain the assumptions and derivation clearly, check edge cases, and show how the result changes when those assumptions no longer hold.
Statistics & MathTechnical Screen - SquarepointMediumQuantitative ResearcherChoose Between an Array and a Linked List
Tests understanding of arrays versus linked lists beyond asymptotic Big O notation, focusing on CPU cache locality, memory layout overhead, reference stability, and practical queue design.
Software Engineering FundamentalsTechnical Screendata-structurescache-localitymemory-hierarchy - SquarepointMediumQuantitative ResearcherCount Files Safely from Bash
Tests command-line proficiency and Bash scripting fundamentals by requiring a robust mechanism to count regular files across a directory tree while handling tricky filenames, symlinks, and recursion correctly.
Software Engineering FundamentalsTechnical Screenbashlinuxshell-scripting - SquarepointMediumQuantitative ResearcherFind Values Whose Removal Minimizes Pairing Cost
Determine all unique values from an odd-length array whose removal leaves an even-length array that can be partitioned into pairs with minimum total absolute difference.
Coding & AlgorithmsTechnical Screenarrayssortingprefix-sum - SquarepointMediumQuantitative ResearcherShortest Subarray with at Least K Distinct Values
Determine the minimum length of a contiguous subarray that contains at least k distinct elements. This problem tests sliding-window techniques, hash map management, and linear-time optimization.
Coding & AlgorithmsTechnical Screensliding-windowhash-tabletwo-pointers - Two SigmaMediumQuantitative ResearcherDaily Temperatures by Town: Linear Models to Predict NYC Temperature
This question evaluates proficiency in ordinary least squares linear regression (with intercept), basic statistical summaries such as standard deviation and median, and model-evaluation metrics like in-sample mean squared error applied to aligned daily time-series temperature data.
Machine LearningTechnical Screen - Two SigmaMediumQuantitative ResearcherLinear Interpolator with Extrapolation
This question evaluates understanding of piecewise linear interpolation and extrapolation, numerical robustness with floating-point values, and algorithmic competencies such as sorting and efficient query location for large datasets.
Coding & AlgorithmsTechnical Screen - Virtu FinancialHardQuantitative ResearcherApproximate a Binomial Upper Tail with a Normal Distribution
This question tests the application of the Normal approximation to the Binomial distribution, the use of continuity correction, and the ability to evaluate the error bounds of this approximation.
Statistics & MathOnsiteStatisticsProbabilityNormal Approximation - Virtu FinancialHardQuantitative ResearcherApproximate a Rare-Event Binomial Probability
This problem tests the application of the Poisson approximation to binomial distributions for rare events and the evaluation of the error bounds associated with this approximation.
Statistics & MathOnsiteProbabilityPoisson DistributionBinomial Distribution - Virtu FinancialHardQuantitative ResearcherBirthday Collisions and the Closest Pair of Birthdays
This problem tests your understanding of probability theory, specifically the generalized birthday paradox, and your ability to analyze spacing distributions of random variables.
Statistics & MathOnsiteProbabilityStatisticsCombinatorics - Virtu FinancialHardQuantitative ResearcherCompare Two Strategies for Getting Ten Consecutive Heads
This problem tests your ability to model probability through recursion and expectation, specifically comparing the efficiency of two distinct strategies for achieving a target streak of coin tosses.
Statistics & MathOnsiteProbabilityExpectationRecurrence - Virtu FinancialHardQuantitative ResearcherMaximum Edges in a Triangle-Free Graph
Determine the maximum number of edges an undirected, simple graph on n vertices can have without containing any triangle (K3), and construct one such extremal graph.
Coding & AlgorithmsOnsitegraph-theorymathcombinatorics - Virtu FinancialHardQuantitative ResearcherMaximum Total Height of Mountain-Shaped Towers Under Per-Plot Height Caps
Each plot in a row has a maximum allowed tower height. Choose tower heights that rise to a single peak and then fall, never exceeding any cap, so that the total height is as large as possible. Tests reasoning about the peak position, per-position caps, and 64-bit sums.
Coding & AlgorithmsOnline Assessment - Virtu FinancialHardQuantitative ResearcherMinimum Number of Transfers to Settle All Debts in a Group
Given a list of past loans between people, compute the minimum number of new money transfers needed so that everyone's net balance returns to zero. Tests reducing a transaction log to net balances and searching for the fewest settling transfers under small input bounds.
Coding & AlgorithmsOnline Assessment - Virtu FinancialHardQuantitative ResearcherReach a Target Pair by Repeatedly Adding One Coordinate to the Other
Starting from a pair of positive integers, each move adds one coordinate to the other. Decide whether an exact target pair can be reached. Tests reasoning about reachability when values go up to one billion and simulating every forward move is far too slow.
Coding & AlgorithmsOnline Assessment - VoleonMediumQuantitative ResearcherBound R-Squared for Individual and Combined OLS Regressions
Derive in-sample OLS R-squared bounds and the joint-model range from individual scores, including intercept assumptions, predictor correlation, and out-of-sample exceptions.
Statistics & MathTechnical Screen - VoleonMediumQuantitative ResearcherExplain a Sorting Algorithm Such as Merge Sort: Mechanics, Correctness, Complexity
Explain a sorting algorithm of your choice, such as merge sort, in a technical screen for a quantitative role. Tests whether you can describe the split and merge steps, trace a small example, argue correctness, derive time and space complexity, and discuss stability and alternatives.
Software Engineering FundamentalsTechnical Screen - VoleonMediumQuantitative ResearcherReason About Train and Test Loss Under Regularization and More Data
Reason about train/test gaps, high losses, regularization strength, and learning curves while separating statistical tendencies from finite-sample guarantees.
Machine LearningTechnical Screen - VoleonMediumQuantitative ResearcherReturn Words in Repeated Anagram Groups
Return all input occurrences belonging to repeated anagram groups, preserving order and duplicates with multiplicity-aware letter-count signatures.
Coding & AlgorithmsTechnical Screen
Point72
Squarepoint
Two Sigma
Virtu Financial
Voleon