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Optiver Trading OA Experience: Mental Math + Probability + Market Making | 2026

2026-05-12

Optiver's Trading OA is fundamentally different from their SWE assessment — it tests mental math speed, probabilistic reasoning, and market making intuition rather than coding ability. This guide covers the assessment structure and preparation strategies.

Assessment Structure

Module Content Duration Weight
Mental Math Fast arithmetic operations 8 min High
Numerical Reasoning Data/chart analysis 20 min Medium
Probability Reasoning Expected value & probability 25 min High
Market Making Sim Quoting strategy game 15 min High
Personality Test Behavioral assessment 15 min Low

Module 1: Mental Math

What's Tested

Complete many calculations in very short time:

Speed Techniques

1. Multiplication shortcuts
   - Near-integer method: 67 × 43 = 67 × 40 + 67 × 3 = 2881
   - Cross multiplication for two-digit numbers

2. Fraction comparison
   - Cross multiply: 7/13 vs 11/19 → 133 vs 143 → latter is larger

3. Percentage shortcuts
   - 10% base method: 847 × 17% ≈ 84.7 + 59.3 = 144.0

Module 2: Probability Reasoning

Example 1: Combinatorics

Bag with 5 red and 3 blue balls. Draw 3 without replacement. P(exactly 2 red, 1 blue)?

P = C(5,2) × C(3,1) / C(8,3) = 30/56 = 15/28 ≈ 0.536

Example 2: Expected Value (Markov Chain)

Fair coin flipped repeatedly. Expected flips until two consecutive heads?

E0 = 6 flips (solved via state equations)

Example 3: Decision Making

Choose between:

EV(A) = $50, EV(B) = $60 → B is better in expectation

Module 3: Market Making Simulation

Key Strategies

  1. Initial spread: Set reasonable width based on uncertainty
  2. Bayesian updating: Adjust quotes based on trade direction
  3. Inventory management: Skew quotes to reduce position risk
  4. Risk control: Widen spread during high uncertainty

FAQ

Does Optiver Trading OA require coding?

No. The Trading OA has zero coding — it tests mental math speed, probability reasoning, and market making intuition. Completely different from the SWE OA.

How fast is the mental math test?

Typically 80 questions in 8 minutes (~6 seconds per question). Both speed and accuracy matter. Practice at least 30 minutes daily.

How do I prepare for the market making game?

Use TraderMath.org's market making simulator. Core concepts: bid-ask spread, Bayesian updating, inventory management. Optiver's Ready Trader Go competition is also great practice.

Can I apply for both Trading and SWE at Optiver?

Yes, the OAs are completely independent. Choose based on your strengths — Trading values math and intuition, SWE values coding and system design.

What's the compensation for Optiver Trading Intern?

Optiver Trading Intern compensation is among the highest in quant: annualized $250K-$400K+ (base + performance bonus).


Preparing for Optiver Trading OA?

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