What Makes Optiver Interviews Different
Optiver's interview process is one of the most demanding in the trading industry. Before you speak to anyone, you sit a battery of timed online tests, for years led by the famous 80 in 8 mental arithmetic sprint. If you can't do two-digit multiplication and decimals in your head at speed, you are unlikely to get past the first round.
Founded in Amsterdam in 1986, Optiver is a global market maker that trades on virtually every major exchange. They handle millions of transactions daily across equities, options, ETFs, bonds, and commodities from offices in Amsterdam, Chicago, Sydney, London, and Shanghai. The firm is known for its engineering-driven culture and its obsession with speed - both in execution latency and in how fast its people can think.
This guide covers the full interview process, the types of questions you'll face, and how to prepare. If you're also applying to other quant firms, our quant interview questions guide covers broader preparation across the industry.
The Optiver Interview Process
Optiver publishes the outline of its process but not the details. Here is the pipeline, with what is official and what comes from candidates marked as such:
Stage 1 - Online Assessments Candidates report the invite arriving within minutes to days of applying. The tests run on what Optiver calls the Optiver Assessment Portal. Trader and researcher candidates get timed arithmetic, sequence and probability modules plus short cognitive games; software engineers get a coding test instead. The modules are covered in detail below.
Stage 2 - Behavioural Interview Optiver's Europe recruitment FAQ describes an "initial behavioural interview" with a recruiter after the assessments. Expect motivational questions ("Why Optiver? Why market making?"), and for trading roles possibly some light probability.
Stage 3 - Technical Interviews Candidates describe probability and expected value questions, market-making games and, for engineers, coding and systems questions. The number of rounds varies by role and office.
Stage 4 - Final Day Optiver refers officially to a "final-day interview". Candidates describe more senior interviews on trading intuition, fit and harder technical problems, and for traders, trading games with other candidates.
Timelines vary by cycle and role, and Optiver says it cannot give specific feedback in the early stages.
The Online Assessment
This is the part everyone talks about. None of the format details below is published by Optiver; they come from candidate reports and prep sites, and they conflict in places.
The 80 in 8. 80 arithmetic questions in eight minutes, six seconds each, with no calculator. Candidates consistently describe it as multiple choice with four options, +1 for a correct answer and -1 for a wrong one, on whole numbers, decimals and fractions. Optiver publishes no pass mark; the most repeated figure is about 55 to 56 net, and 70 or more is commonly called competitive.
Is it still used? The 2026/27 invites that candidates have quoted list Beat the Odds, NumberLogic and three new modules (Likelihood-list, Intervals and Orderbooks), with no 80 in 8. One prep site says it is still used in 2026 but cites no invite, so its current status is unconfirmed. Our Optiver 80 in 8 guide sets out the evidence on format, scoring, pass marks and whether it is still used.
The other modules, as candidates describe them:
- NumberLogic: number sequences, commonly reported as 26 questions in 25 minutes with a calculator allowed.
- Beat the Odds: probability questions; reported sizes conflict, and the 2026 invite gives 25 minutes.
- Zap-N: short cognitive games of two to 15 minutes each.
- Likelihood-list, Intervals and Orderbooks (new for 2026): ranking outcomes by probability, giving tight confidence intervals, and finding profitable combinations of buys and sells.
The rules around the tests are official. Optiver's Europe FAQ says "assessments can only be completed once every 8 months". Results are reused for similar roles within that window, and Optiver cannot reset an attempt once it has started. So your first sitting is the one that counts.
For how other firms' tests compare, see our quant online assessments guide.
Mental Maths Practice Questions
Try these under timed conditions - give yourself 6 seconds each:
- 37 × 13 = ? Break it down: 37 × 10 = 370, 37 × 3 = 111, total = 481
- 84 × 26 = ? Use: 84 × 25 = 2100, 84 × 1 = 84, total = 2184
- 1728 / 12 = ? 12 × 144 = 1728, so the answer is 144
- 456 + 378 = ? 456 + 400 = 856, minus 22 = 834
- 63 × 47 = ? Use: 63 × 50 = 3150, minus 63 × 3 = 189, total = 2961
- 2.5 × 3.6 = ? Think: 25 × 36 = 900, move decimals = 9.0
- 5600 / 35 = ? 35 × 160 = 5600, so 160
- 88 × 12 = ? 88 × 10 = 880, 88 × 2 = 176, total = 1056
The key technique is to decompose problems into easier parts. Multiply by rounding to the nearest 10 or 25, then adjust. For division, ask yourself what multiplied by the divisor gives the dividend.
Roles and How Interviews Differ
Optiver hires across four main technical tracks. Candidates report that the online tests already differ by track, and the later rounds diverge further.
Trader
The most competitive track. After the maths test, traders face probability questions, options pricing theory, market making simulations, and extensive trading games. Interviewers look for quick decision-making under uncertainty, intellectual curiosity, and composure. You don't need a finance degree, but you do need strong quantitative reasoning and a willingness to take calculated risks.
Quantitative Researcher
Quant researchers get deeper statistical and mathematical questions. Expect time series analysis, regression, hypothesis testing, and potentially questions on signal processing or machine learning. If you're interested in this path, our guide to becoming a quant covers the educational background you'll need.
Software Engineer
Software engineers get a different online stage: candidates report a HackerRank coding test and the Zap-N games rather than the arithmetic modules. The interviews that follow are algorithmic. Expect data structures, algorithms, system design, and questions about low-latency programming. C++ and Python are the primary languages. Optiver cares deeply about performance-critical code - you may be asked about cache behaviour, memory allocation, or lock-free data structures.
FPGA Engineer
A more specialised track focusing on hardware description languages (VHDL or Verilog), digital logic design, and low-latency networking. These interviews are highly technical and specific to the domain.
Types of Questions You'll Face
Beyond the initial maths test, Optiver interviews cover several question categories depending on your role.
Probability and Expected Value
These come up in every technical round for trading and research roles. They test whether you can reason about uncertainty quickly and correctly. Our probability fundamentals article covers the essential theory.
Example: You roll two dice and multiply the results. What's the expected value?
Approach: E[X × Y] = E[X] × E[Y] when X and Y are independent. E[single die] = 3.5. So E[product] = 3.5 × 3.5 = 12.25.
Example: You flip a coin repeatedly. You win £2 for heads and lose £1 for tails. What's the expected value per flip, and would you play?
Approach: E = 0.5(2) + 0.5(-1) = £0.50 per flip. Yes, you'd play - it's positive expected value.
Market Making and Pricing
These questions test whether you understand how market makers think about risk and inventory.
Example: I tell you a jar contains between 500 and 1500 marbles. Make me a market (bid-ask) on the number of marbles.
Approach: Your fair value estimate is 1000 (midpoint). Start with a wide spread - maybe 800 at 1200. The interviewer will trade with you. Adjust your estimate based on whether they buy or sell, and tighten your spread as you gain information. If they keep buying, your estimate should shift upward.
Example: You're market making on a stock currently at £50. A news event has a 60% chance of being positive (stock goes to £55) and a 40% chance of being negative (stock goes to £42). Where do you set your bid and ask?
Approach: Fair value = 0.6(55) + 0.4(42) = 33 + 16.8 = £49.80. Your spread should be wide enough to protect against adverse selection but narrow enough to attract flow. Something like £48.50 at £51.00 would be reasonable - you'd explain your reasoning about the asymmetric risk.
Trading Games and Simulations
The trading game is often the highlight of Optiver's assessment day. You'll typically be placed in a simulated market with other candidates, given a product to trade, and judged on your P&L, risk management, and behaviour.
Common formats include:
- Card-based games: A deck of cards represents uncertain information. You trade a "stock" whose value depends on the cards revealed. You need to update your fair value estimate as new information arrives and manage your position.
- Multi-round simulations: You trade over multiple rounds with new information each round. The game tests whether you can keep a clear head, manage inventory, and avoid getting picked off.
- Competitive market making: You and other candidates simultaneously quote bid-ask spreads. The best spreads get filled. You need to balance being competitive on spread with managing risk.
The most important thing in trading games isn't finishing with the highest P&L. Interviewers watch how you think, how you update beliefs, and whether you stay disciplined. Panicking after a loss or becoming reckless after a win are both red flags.
Coding Questions (Engineering Roles)
Software engineers face LeetCode-style problems plus systems questions:
Example: Implement an order book that supports limit orders, market orders, and cancellations. What data structures would you use for O(1) best bid/ask lookup?
Approach: Use a sorted map (or balanced BST) keyed by price level, with each level holding a queue of orders. Maintain pointers to best bid and best ask. For cancellations, use a hash map from order ID to its location in the book.
Quick quiz
Quick Optiver-style warm-up
Three short checks — the kind of thinking the process rewards.
What is 47 × 53? (mental maths style)
How to Prepare
Preparing for Optiver requires a different approach from standard tech or finance interviews. Here's what actually works.
Mental Maths (Start 4-6 Weeks Before)
This is non-negotiable. Practice every single day.
- Use Quantt's free 80 in 8 challenge for the pace and the +1/-1 penalty. It uses typed answers and whole numbers, so add decimals and fractions by hand. Zetamac is also useful for extra timed volume. Work toward 80 questions in 8 minutes with over 90% accuracy.
- Drill multiplication tables up to 20 × 20 from memory.
- Practise squaring two-digit numbers: 37² = (40 - 3)² = 1600 - 240 + 9 = 1369.
- Learn to multiply by breaking numbers apart: 67 × 43 = 67 × 40 + 67 × 3 = 2680 + 201 = 2881.
- For division, build intuition for common factorisations: know that 144 = 12², 225 = 15², and so on.
Probability and Statistics (2-4 Weeks Before)
Work through classic quant interview questions focusing on expected value, conditional probability, and Bayes' theorem. Make sure you can solve problems like the Monty Hall problem, the birthday paradox, and the gambler's ruin without hesitation.
Trading Intuition (2-3 Weeks Before)
Read about how market making works. Understand bid-ask spreads, inventory risk, and adverse selection. Our quant trading strategies article covers the fundamentals. Play poker if you don't already - the skills of reading incomplete information, managing risk, and making +EV decisions under uncertainty translate directly.
Mock Interviews (1-2 Weeks Before)
Practise with friends. Have someone fire rapid mental maths questions at you. Simulate trading games with cards. The pressure of performing in front of someone else is genuinely different from solo practice.
What Optiver Looks For
Beyond raw technical ability, Optiver evaluates several traits consistently:
- Speed of thought - Can you process information and reach a conclusion quickly? This matters more at Optiver than at almost any other firm.
- Intellectual curiosity - Do you ask good questions? Do you probe deeper when something doesn't make sense?
- Composure under pressure - How do you react when you're wrong, when you're losing money in a game, or when a question is beyond your current knowledge?
- Collaborative mindset - Market making is a team sport. Optiver wants people who communicate clearly and work well with others, not lone wolves.
- Calibrated confidence - Know what you know, and be honest about what you don't. Bluffing is worse than admitting uncertainty.
Compensation & recruiting notes
Pay ranges in this guide are illustrative estimates from publicly discussed bands and anecdotal reports - not official figures from the employer. Packages vary widely by desk, office, performance, and year. Hiring processes change; nothing here guarantees an interview, assessment format, or offer.
Frequently Asked Questions
How hard is the Optiver maths test?
Harder than it sounds. The individual questions are basic arithmetic, but at six seconds each across 80 questions, with decimals and fractions mixed in and a penalty for wrong answers, unprepared candidates struggle. Several weeks of daily timed practice is the usual preparation. Note that the 2026/27 invites candidates have quoted do not include the 80 in 8 at all; see our 80 in 8 guide for the evidence.
Do I need a finance background to interview at Optiver?
No. Optiver hires from mathematics, physics, computer science, engineering, and other quantitative disciplines. Many successful traders have no formal finance education. What matters is quantitative reasoning ability, speed of thought, and intellectual curiosity. That said, understanding basic options concepts and market making principles will help in later interview rounds.
What programming languages does Optiver use?
Optiver's technology stack is primarily C++ for performance-critical trading systems, with Python used for research, data analysis, and tooling. FPGA engineers work with VHDL or Verilog. For software engineering interviews, you'll typically code in C++ or Python, though the focus is on problem-solving rather than language-specific syntax.
How long does the Optiver interview process take?
Optiver does not publish a timeline. Candidates report the online assessment invite arriving within minutes to days of applying, with a window of a few days to a week to complete it. After that, the behavioural interview, technical rounds and final day depend on scheduling, the role and the office.
Can I retake the Optiver maths test if I fail?
Not for eight months. Optiver's Europe recruitment FAQ says assessments "can only be completed once every 8 months", that earlier results are reused for similar roles within that window, and that it cannot reset an attempt once started. Use the gap for daily practice on the 80 in 8 simulator and probability work, and treat your first sitting as the real one.
How does Optiver's interview compare to Jane Street or Citadel?
All three firms are demanding, but the emphasis differs. Optiver places uniquely heavy weight on raw arithmetic speed through its maths test. Jane Street is known for longer, more open-ended probability and estimation problems with extended back-and-forth discussion. Citadel's process varies more by team but often includes heavier coding components. Our quant interview questions guide covers preparation strategies that work across all three.
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