DRW 2026 Summer Quant/QR Intern OA Full Review

DRW’s 2026 Summer Quant / Quant Research Intern OA is notoriously hardcore.

You are given 6 questions in 45 minutes, covering mathematical reasoning, probability & statistics, and brainteasers. With only 7.5 minutes per question, hesitation is often more dangerous than difficulty.

Below is a streamlined, practical breakdown of what the OA really tests and how to prepare efficiently.

Core Assessment Focus

The OA is tightly aligned with DRW’s core businesses: Liquidity Providing, Risk Taking, and Latency-Sensitive Trading. As a result, it prioritizes:

Mathematical fundamentals
- Linear algebra
- Calculus basics
Probabilistic thinking
- Expectation
- Conditional probability
- Recursive reasoning
Dynamic programming & state modeling
Fast, accurate problem-solving under time pressure

DRW is not testing fancy tricks — it is testing whether you can think clearly and compute correctly under severe time constraints.

Key Question Breakdown & Quick Solutions

1. Coin Expectation (Warm-Up)

Task:

A coin lands heads with probability 0.8. Each head pays $80.

Compute the expected number of heads in 100 flips and the expected payout.

Solution:

Expected heads: 100 × 0.8 = 80
Expected payout: 80 × $80 = $6,400

Tip:

No trick here. Solve quickly and move on.

2. Matrix Null Space & L2 Norm

Task:

Find the L2 norm of vector y projected onto the null space of matrix A.

Key Steps:

Solve Ax = 0 to find the null space basis
Project y onto the null space
Compute the L2 norm of the projection

Reference Answer: 1.630

Tip:

This is a high-frequency DRW linear algebra pattern — practice until automatic.

3. Normal Distribution Quantization

Task:

For X ~ N(0, 3), define

Q(x) = c if x ≥ 0
Q(x) = −c if x < 0

Minimize E[(X − Q(X))²].

Solution Strategy:

Use numerical optimization with Python:

scipy.optimize.minimize
scipy.stats.norm.expect

Optimal Result:

c* ≈ 0.798

Tip:

Manual integration is slow and error-prone. Numerical methods save time.

4. 7-Sided Die Collection (Recursive Probability)

Task:

Roll a fair 7-sided die.

You must collect all 7 distinct sides.

After collecting 6 sides, rolling any previously seen side resets the process (rolls still count).

Key Insight:

This is a recursive expectation problem.

Let E = expected total rolls
Let E₆ = 1 + (6/7)E

Combine with the expected time to collect the first 6 sides (coupon collector logic).

Final Result:

E ≈ 85.050

Common Pitfall:

Forgetting that rolls still accumulate after a reset.

5. Step Probability with Coin Flips (DP)

Task:

Start at step 0.

Heads → +1 step
Tails → +2 steps

Let pₙ be the probability of ever landing exactly on step n.

Compute 1000 × (p₄ + p₁₀).

Recursive Formula:

p₀ = 1
p₁ = 0.5
pₙ = 0.5 pₙ₋₁ + 0.5 pₙ₋₂

Final Result:

≈ 1354.492

Tip:

Do not enumerate paths. Dynamic programming is essential.

Preparation Tips

Focus on high-frequency topics
- Probability & statistics
- Linear algebra
- DP / recursion
Practice with strict timers
- Max 8 minutes per question
Master tools in advance
- numpy, scipy, numerical optimization
- Reusable code templates save minutes

Pro Tip: Professional Guidance Saves Time

Many candidates fail not due to lack of intelligence, but because of:

Weak recursive modeling
Poor time allocation
Overthinking simple questions

ProgramHelp’s mentors (2–8 years at top quant firms) provide:

Targeted mock exams with real OA pacing
Clear frameworks for recursion & DP problems
Ready-to-use code templates for quant OAs
Affordable pricing — no overpriced “packaging”

Instead of struggling alone, focused guidance can compress weeks of trial-and-error into days.

Final Takeaway

DRW’s OA does not test whether you can solve “hard problems.”

It tests whether you can solve practical mathematical problems quickly and accurately under pressure.

With targeted practice, solid fundamentals, and efficient strategies, passing the DRW OA is absolutely achievable.

Good luck with your DRW 2026 Summer Intern application 🚀