Barclays Interview Questions
72 real Barclays quant and strategist questions spanning derivatives pricing, statistics and time-series, market microstructure, and algorithmic coding.
Inside the Barclays interview
Barclays is a global investment bank whose quant and strategist desks sit at the seam of derivatives pricing, statistical modeling, and production code. Interviews for Quant Analyst and Strategist roles favor depth in stochastic calculus and econometrics over speed puzzles.
What they test
The three pillars are nearly even. Options pricing & derivatives runs deep — put-call parity with dividends, American early exercise, barrier in/out parity, butterfly/convexity arbitrage, Merton jump-diffusion, variance-swap replication, and Almgren-Chriss execution. Beside it, a heavy statistics & time-series core (MLE, Bayesian updating, GARCH/EWMA, cointegration, CUSUM/change-point) and a real algorithmic coding bar (selection, segment trees, monotone deques, streaming quantiles).
The recurring shapes
Expect no-arbitrage reasoning on option surfaces (convexity in strike, in/out parity, ETF creation-redemption thresholds), likelihood and posterior machinery (GBM drift/vol MLE, Gamma-Poisson and g-prior Bayes, no-trade-event updates), and market-microstructure models where Glosten-Milgrom zero-profit quotes and inventory-aware skew show up. Coding rounds want clean, correct algorithms, not tricks.
How to approach
Lead with the economic invariant (replication, hedging error, zero-profit condition), then formalize it — write the SDE, the log-contract, or the likelihood and turn the crank. For the stats blocks, be fluent moving between estimator, its variance (HAC/block-bootstrap), and a test statistic. For coding, state the invariant and complexity before you type.
Roughly half the set is hard — dense derivatives and econometrics — with a solid medium layer of pricing, Bayesian, and coding problems and a few easy warm-ups.
Barclays coding questions (16)
- Median-of-Medians Selection (BFPRT)
- Bucket Sort for Uniform Samples
- Sliding Window Maximum and Minimum with Monotone Deques
- Streaming Approximate Quantiles with Rank-Error Guarantees
- Johnson's Algorithm for All-Pairs Shortest Paths
- Longest Substring Without Repeating Characters
- Randomized Quickselect Expected Runtime
- Inverse Transform Sampling for a Piecewise-Linear CDF
- Longest Increasing Subsequence in O(n log n)
- Range Minimum Query via Sparse Table
- 24 Game Solver
- Fast-Doubling Fibonacci with Modular Arithmetic
- Union-Find with Path Compression and Union by Rank
- Inversion Count and Shortest Subarray With Sum at Least K
- 2D Fenwick Tree for Rectangle Sum Queries
- Digit Percentage in Strings
Barclays statistics questions (15)
- Gamma-Poisson Conjugate Updating
- Online Covariance and Correlation (Welford-Style)
- Tracking Error Estimation with HAC-Robust Inference
- Sequential Probability Ratio Test for Poisson Arrivals
- Block Bootstrap Confidence Interval for Sharpe Ratio
- Isotonic Regression and the Pool-Adjacent-Violators Algorithm
- MLE for Student-t Location-Scale via IRLS
- Bayesian Regression with Zellner's g-Prior
- Ljung-Box Test for Serial Correlation in Returns
- ROC AUC as the Wilcoxon-Mann-Whitney Statistic
- Bayesian Online Change-Point Detection for a Normal Mean
- MLE for GBM Drift and Volatility
- Bayesian Update from a No-Trade Event
- One-Sided CUSUM for Detecting a Mean Shift
- Bayesian A/B Test for Conversion Rates
Barclays options pricing questions (13)
- ETF Creation/Redemption Arbitrage Threshold
- Inventory-Aware Spread and Skew
- Butterfly Arbitrage and Convexity of Call Prices in Strike
- Avellaneda-Stoikov Optimal Quotes with CARA Utility
- Almgren-Chriss Mean-Variance Optimal Execution
- Merton Jump-Diffusion European Call Price
- Variance Swap Fair Strike via Log-Contract Replication
- GARCH(1,1) with Student-t Innovations: VaR and Tail Risk
- Put-Call Parity Arbitrage with Dividends
- Discrete Delta-Hedging Error
- Monte Carlo Pricing of Arithmetic Asian Options with Variance Reduction
- American Option Early Exercise Analysis
- Barrier Option In/Out Parity
Barclays time series questions (6)
Barclays market microstructure questions (4)
Barclays regression questions (3)
Barclays expected value questions (3)
Barclays linear algebra questions (2)
Barclays random variables questions (2)
Barclays probability questions (2)
Barclays optimization questions (2)
Barclays machine learning questions (1)
Barclays stochastic processes questions (1)
Barclays finance questions (1)
Barclays game theory questions (1)
Barclays interview FAQ
What kind of questions does Barclays ask in quant interviews?
Candidates most often report coding, statistics and options pricing questions. This page collects 72 of them, 71 stamped with the month they were last reported — each with a full worked solution.
How hard are Barclays interview questions?
The set spans 2 easy, 29 medium and 41 hard problems. Most sit at medium difficulty — solvable in a few minutes with clean reasoning — with a harder tail that rewards knowing the canonical tricks.
How do I prepare for the Barclays quant interview?
Work through this set by topic (use the sidebar), starting from your weakest area. 10 problems are free to open with their full solution, so you can judge the quality before anything else. Then broaden out with the related firms below — the question families overlap heavily.
Are these the actual Barclays interview questions?
They are built from candidate-reported Barclays questions. We rewrite each prompt for clarity and author the worked solutions ourselves — we don't claim the wording is verbatim, and we never invent questions or recycle generic lists. 71 of 72 carry the month they were last reported.