Old Mission Capital Interview Process & Prep

Old Mission is a Chicago-based proprietary trading firm and options/ETF market maker. The process starts with an online assessment, then several technical rounds heavy on probability, expectation, and mental math, with options and market-making intuition for trading roles and clean coding for engineers. There is no scripted game on this page -- the bar is fast, accurate probabilistic reasoning and trading sense.

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The Old Mission Capital interview funnel

1. Online Assessment

Timed - math + coding

The process opens with a timed online assessment covering quantitative/probability questions and (for engineering) coding. Speed and accuracy both matter.

2. Probability & Mental Math

45-60 min - video

Core probability, expectation, statistics, and mental math under time pressure, with follow-ups. This is the heart of the trading screen.

3. Options & Market-Making Round

45-60 min - trading intuition

For trading roles: options basics, pricing intuition, market-making (quote a market, manage risk), Kelly sizing, and game-theory-flavored decision problems.

4. Onsite - Hardest Rounds

Final rounds - the toughest reported problems

The hardest reported Old Mission problems across every topic -- probability, options/market-making, Kelly sizing, and coding. (These are the hard-rated problems; the earlier rounds cover the easy/medium set, so nothing here repeats.)

Old Mission Capital interview — FAQ

What is the Old Mission Capital interview process?

Old Mission is a Chicago-based proprietary trading firm and options/ETF market maker. The process starts with an online assessment, then several technical rounds heavy on probability, expectation, and mental math, with options and market-making intuition for trading roles and clean coding for engineers. There is no scripted game on this page -- the bar is fast, accurate probabilistic reasoning and trading sense. The loop runs 4 stages: Online Assessment, Probability & Mental Math, Options & Market-Making Round, Onsite - Hardest Rounds.

How many rounds does Old Mission Capital have?

4 stages in total, starting with the Online Assessment and ending with the Onsite - Hardest Rounds.

How do I prepare for the Old Mission Capital interview?

Work the stage notes above, then drill the Old Mission Capital interview-questions set and the Old Mission Capital online-assessment practice — each problem has a full worked solution.