Many people prep for Optiver by grinding OA problems alone, then pass the OA only to stumble on the mental-math screen or the Super Day. Optiver's selection is a full pipeline, and each stage tests a different skill. This article lays out a systematic prep route from OA to final round, with a four-week study plan.
Optiver Full Process Overview
| Stage | Format | Focus |
|---|---|---|
| OA | Online, timed | Coding simulation + mental math/probability |
| Mental Math Test | 80 questions in 8 min | Fast arithmetic, fractions, negatives |
| Technical Phone Screen | Video | Coding + probability reasoning |
| Super Day | Multiple onsite rounds | Coding, market questions, behavioral, cases |
Step 1: Master the OA Question Types
The Optiver OA usually has 2–4 questions centered on simulation and probability. Practice order-book matching and event-queue processing for simulation; expected value and conditional probability for probability.
# Expected-value template: linearity of expectation, no simulation needed
def expected_value(outcomes, probs):
# outcomes and probs correspond one-to-one, sum(probs) == 1
return sum(o * p for o, p in zip(outcomes, probs))
Step 2: Conquer the Mental Math Test (Most Underrated)
Optiver's famous 80-questions-in-8-minutes test gives you ~6 seconds per question. It covers integer, fraction, decimal, and negative arithmetic. This stage is not about tricks but deliberately practiced speed.
Training approach:
- Use an online mental-math tool to do timed sets of 80 daily
- Focus on fractions and negatives (where people stall most)
- Goal: reliably get 60+ correct
Step 3: Technical Phone Screen and Probability Reasoning
The screen often poses card/dice/ball conditional-probability questions requiring fast verbal reasoning.
# Conditional probability: P(A|B) = P(A∩B) / P(B)
def conditional_prob(p_a_and_b, p_b):
return p_a_and_b / p_b
Force yourself to talk through your reasoning while computing, because the interviewer evaluates the process, not just the answer.
Step 4: Super Day
Includes coding deep-dives, market/estimation questions (e.g. "estimate how many gas stations are in New York"), behavioral, and trading case discussions. Show structured thinking and risk awareness.
Four-Week Study Plan
| Week | Focus |
|---|---|
| Week 1 | LeetCode Medium (heap, stack, simulation) + daily mental math |
| Week 2 | Probability/expectation topics + order-book simulation |
| Week 3 | Conditional-probability verbal drills + estimation |
| Week 4 | Full-process mocks + behavioral STAR prep |
Recommended Practice Areas
| Type | LeetCode Reference |
|---|---|
| Simulation/order book | 933, 346, 155 |
| Heap/priority queue | 215, 295, 23 |
| Greedy/execution | 122, 621, 134 |
Optiver prep can't be lopsided. Coding, mental math, and probability must advance together — any single weak spot can knock you out.
FAQ
How long does Optiver prep take? With algorithm fundamentals, four weeks of systematic prep is usually enough; start the mental-math test early, since it relies most on long-term muscle memory.
Does the mental-math test matter much? A lot. Many technically strong candidates get stuck here — practice daily.
What skills does Optiver value? Fast, accurate numeric computation, probability intuition, structured communication, and risk awareness — far beyond coding.
Can I get into Optiver without a math/finance background? Yes. Optiver values thinking ability over major; solid probability and mental-math practice can close the gap.
How do I prep for the Super Day market questions? Practice Fermi estimation (e.g. "estimate the number of taxis in a city"), breaking complex problems into quantifiable steps with a clear reasoning chain.
Preparing for the full Optiver process?
The challenge is balancing coding, mental math, and probability all at once. Our mentors offer systematic breakdowns and mocks from OA types and mental-math sprints to Super Day case questions. For a tailored study plan, reach out — contact WeChat Coding0201 to get real questions and prep materials.
Contact
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