Old Mission Capital Careers: Salaries & Internships

Old Mission is a quantitative market maker: it prices financial instruments and provides liquidity using its own technology, models and risk management. If you searched “old mission capital” to find the employer, these are the direct destinations.

The company traces its market-making platform and ETF origins to 2008. Its contact page lists Chicago, New York and London. The website identifies Old Mission Capital LLC and Old Mission Markets LLC as US service entities within Old Mission Group LLC. Platform history and entity information, company history, offices.

This is an independent career guide. It is useful for choosing a track and preparing evidence; the employer's current posting and your recruiting contact determine your actual application requirements.

Old Mission's public business description covers liquidity in equities, bonds, currencies and derivatives. Researchers develop models from data; engineers build execution systems; traders manage execution and portfolio risk. Its history begins with an ETF-market opportunity, but today's career search should include the particular desk and product named in the vacancy. Business description, history.

An ETF market maker quotes prices at which it is willing to buy and sell ETF shares. An authorised participant has an agreement with the fund to create or redeem blocks of shares. These are different functions: the SEC's ETF bulletin explains that creation exchanges a designated basket and cash for ETF shares, while redemption reverses that exchange. Secondary-market prices can still differ from net asset value. SEC ETF bulletin.

For a candidate, the useful questions are concrete. How fresh are the basket prices? What changes if an underlying market is closed? Can you execute the hedge at the estimated price? What exposure remains while you hold inventory? Answering these makes “I am interested in market making” much more informative than naming a trading strategy.

These are selected employer postings observed on 3 October 2026, not a complete job board or a guarantee that applications remain open. QR means quantitative researcher; QT means quantitative trader. Each linked employer description supplies the requirements for that particular role and office.

Read titles and requirements together. The QR programme title includes “Ph.D.”, while its requirements allow a master's or PhD. Ask recruiting about that discrepancy rather than assuming either universal PhD eligibility or automatic acceptance with a master's. The micro-internship also uses undergraduate-degree wording alongside a future graduation requirement; confirm how that applies to your enrolment.

Descriptions can be revised. Reopen the linked job and save its title, office, programme year and requirements when you apply.

The numbers above are advertised base pay for particular vacancies. They are stronger evidence than a company-wide estimate, but they still do not establish average earnings or the package you would receive. US graduate trading and London graduate trading are different postings with different disclosures.

For the software internship, the source labels US$150,000–200,000 as a base range without specifying a pay period. It does not say an intern receives that amount over the summer. Ask the recruiter for the hourly or weekly rate and programme duration before calculating earnings. The trading micro-internship states a weekly amount explicitly. Software internship, trading micro-internship.

Compare an offer using four separate figures: fixed base, any signing payment, any explicitly guaranteed payment, and discretionary bonus. Record currency, office, payment dates and conditions. Treat an unspecified bonus as unknown. Do not turn a base range plus “discretionary bonus” into a promised total-compensation band.

The Chicago trading micro-internship runs 4–22 January 2027. Its description includes strategy exploration, mock trading, quantitative research and related software, with classroom and desk learning. It names December 2027 or May 2028 graduation and Python familiarity. That is a short winter programme, not evidence of a summer trading internship with the same eligibility. Micro-internship description.

The Chicago software internship starts 1 June 2027. It requires at least junior standing, a relevant bachelor's or master's in progress, minimum 3.0 GPA, and December 2027 or May 2028 graduation. The posting explicitly says prior finance experience is unnecessary and describes hands-on engineering work. Its end date is not stated in the reviewed description. Software internship.

Graduate vacancies include an August 2027 US trading programme, a separate February 2027 US trading programme, and the August-start programmes above. A title's start month does not establish a universal application deadline.

Check availability, graduation eligibility, office, start date and work authorisation before applying. No firm-wide closing date, recruiting turnaround or automatic internship-to-offer conversion was established by the reviewed primary pages. Campus events can show recruiting activity; they do not establish access limited to those universities.

Quantitative research: the linked graduate QR vacancy concerns options and volatility. Prepare to explain model calibration, noisy quotes, stable risk sensitivities and implementation choices. A clean explanation of why a model fails under particular conditions can be valuable evidence. A generic prediction notebook alone does not address a derivatives-focused description. QR posting.

Quantitative trading: practise decisions under uncertainty and keep a position ledger. If someone trades against your quote, distinguish new information about value from a change in your inventory. Show how risk limits affect the next decision. The US graduate vacancy also requires Python or C++; do not assume trading applications are free of programming requirements. US graduate trading.

Production Python: demonstrate reliable software beyond notebooks. A small data-processing service can show clear interfaces, validation, database reasoning, failure recovery and maintainable code. Explain what happens when inputs arrive twice or a dependency fails. The employer asks for professional production experience in its experienced Python role. Python engineer.

Low-latency C++: build evidence around correctness and measured performance. Explain ownership, concurrency, networking and Linux behaviour. Report tail latency as well as average latency, with hardware and workload recorded. A faster benchmark is unhelpful if it loses messages or corrupts state. C++ engineer.

These are independent preparation suggestions mapped to the public descriptions. They are not a claim about the firm's interview scoring rubric.

Use the official careers board and the application form for your exact role. The employer's working-at page describes collaboration, intellectual humility, responsibility and learning on the desk. These are its published culture statements, not independently measured guarantees about every team. Current roles, working at Old Mission.

The reviewed primary pages do not establish a universal assessment platform, round count, passing score or recruiting timeline. Third-party preparation guides and anonymous interview reports can suggest practice topics, but role, office and recruiting cycle may differ. A reported arithmetic test does not prove your invitation contains one.

Before an assessment, check duration, deadline and timezone, calculator/materials rules, coding environment and any accommodation instructions. For an interview, confirm format and whether a project discussion or live implementation is expected. Ask your recruiting contact about missing instructions.

Prepare a concise account of your work: the problem, your contribution, the hardest decision, how you checked the result, and a limitation. For team discussions, explain a time evidence changed your mind. Practise stating an assumption and revising it calmly when challenged. That builds useful communication without pretending to know confidential questions.

This is an original teaching exercise, not an Old Mission strategy or interview question. Assume a hypothetical instrument has estimated fair value US$100.00. You quote 99.96 bid / 100.04 ask, up to 100 shares on each side. Positive inventory means you own shares; negative inventory means you are short. Each executed share costs US$0.005 in fees.

The full quoted spread is 0.08 / 100 × 10,000 = 8 basis points; each execution fee is 0.005 / 100 × 10,000 = 0.5 basis points at that reference price. A basis point is 0.01%. Both are useful inputs to the ledger, but earning the full spread requires an appropriate closing transaction.

1. A customer buys 100 shares at your ask. You sell 100 at 100.04 and receive 10,004 before fees. Your inventory becomes −100. After 0.50 in fees, net cash is 10,003.50. At a 100.00 valuation, mark-to-market profit is:

cash + inventory × mark = 10,003.50 − 100 × 100.00 = US$3.50.

That is unrealised mark-to-market profit on an open short position. It is not a completed spread trade.

2. Adjust for inventory, then for information. To encourage buying back shares, an illustrative inventory adjustment raises the quote to 99.98 / 100.06, holding width at 0.08. Your bid is more attractive to sellers; your ask is less attractive to buyers. This adjustment changes trading incentives; it does not prove fundamental value rose. If the customer's purchase revealed information, your fair-value estimate may need a separate update.

Inventory-sensitive quotes are studied in market-microstructure research, including Avellaneda and Stoikov's inventory-risk model. The two-cent inventory adjustment here is an arbitrary teaching choice, not a calibrated version of that model.

3. Compare two possible closes.

Before closing in the second scenario, marking the short at 100.12 gives 10,003.50 − 10,012 = −US$8.50. Crossing at 100.16 costs another 4.00 relative to that mark, plus 0.50 fees, producing −13.00. The initial spread did not protect you from adverse movement.

4. Add a risk constraint. Suppose the absolute inventory limit is 150 shares. With inventory −100, selling another 100 would breach it. In this toy setting, the next sell size must be at most 50, or selling must stop. Reconcile outstanding orders too: two live sell orders can together breach a limit even if each looks acceptable alone.

A strong explanation tracks cash, position, fees, risk and information separately. In real trading, fills, cancellation timing, tick sizes, hedges, borrow costs and market impact also matter. This example omits them so every arithmetic step can be checked; it does not demonstrate a profitable executable strategy. If spread and execution arithmetic are new to you, the quotes, spreads and execution lesson provides further practice; it is a Pro lesson.

Choose one project matched to the role. Finishing a small, inspectable artifact is more useful than listing several unfinished trading systems.

For research, distinguish information available at the decision time from later data. Keep development and evaluation samples separate where you fit predictive or decision rules. Include a simple baseline and show what changes after fees, delayed execution or perturbed inputs. An attractive result that disappears under a small change deserves investigation.

For engineering, state the throughput/latency objective and what correctness means. Include malformed inputs, empty inputs and overload behaviour; choose checks that expose failure rather than merely repeat implementation.

In every track, supply a short README, instructions to reproduce results, declared data rights, key assumptions and an honest limitations section. Be able to explain one result without scrolling through the entire codebase. Do not present simulated execution as live trading, or public data as privileged employer information.

This schedule is an independent way to organise work. Adjust it to the requirements you already meet and the time available; four weeks does not make every applicant ready.

Use the first session to make a gap table: requirement, evidence you have, missing evidence and next action. If a vacancy asks for professional experience you lack, a side project does not silently replace it; look at a suitable graduate or internship role.

End preparation with a decision, not another resource list. Can you explain the central technical choice? Can another person reproduce the result? Can you name a failure condition? Those are useful readiness signals across the four tracks.