Jobs › Simplex Trading

Algorithmic Trader

Simplex Trading · Chicago, IL · $150,000–$200,000 a year · Trading

Posted Sep 11, 2026 · We last checked this listing on Oct 6, 2026

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Likely interview questions for this role

Written from this job description, not a generic list. Each one notes what the interviewer is really checking.

About your past

Tell me about an algorithmic strategy you worked on. What was its edge and how did you know it was real?

What they are checking: Whether they can separate true edge from noise or overfitting.

You work closely with our technology team. Tell me about a time you and a developer disagreed on how to build something.

What they are checking: Ability to collaborate with engineers and find solutions both sides trust.

Tell me about a time a system you designed failed in an unexpected way.

What they are checking: Whether they design robust systems and learn from edge cases.

What would you do

A strategy that was profitable last month is now losing money. Walk me through how you find out why.

What they are checking: A methodical, data-focused troubleshooting process, which the posting stresses.

If you wanted to expand into a new product, how would you decide if it is worth it?

What they are checking: Business thinking about market share growth, costs and competition, as the posting mentions.

What data would you want to see every morning to know your strategies are healthy?

What they are checking: Whether they have a habit of monitoring and catching problems early.

About the work

How does market microstructure affect how you would quote equity or futures options?

What they are checking: Understanding of queue position, tick size, fees and adverse selection that drive market making results.

How would you tune the parameters of a trading model without overfitting to past data?

What they are checking: Statistical discipline with out-of-sample tests and simple models.

What risk limits would you put on an automated options strategy, and why?

What they are checking: Whether they think about Greeks, position limits and kill switches before scaling up.

How do you measure the quality of order execution?

What they are checking: Familiarity with slippage, fill rates and markouts as ways to judge execution.

Here is a simple problem: you flip a fair coin until you get two heads in a row. What is the expected number of flips?

What they are checking: Quick, clear probability reasoning that trading firms rely on for fast decisions.

Practice this interview out loud.

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The full job description

As published by Simplex Trading.

Our employees are our greatest asset. We have spent years building a team of talented, dedicated technologists, data-driven traders, and expert leaders with an emphasis on our core pillars: People, Process, Trading Edge, and Technology. Simplex is an in-office organization, helping to foster a collaborative and communicative culture. Career Description Simplex is looking for analytical and creative individuals to join our trading team.  Traders at Simplex work closely with our technology team to design and optimize algorithmic trading strategies based on deep knowledge of market microstructure, trading  dynamics, and data-focused understanding of pricing, risk management, and order flow.  An ideal candidate is collaborative, strongly self-motivated, and capable of detail-oriented troubleshooting, data analysis, and robust systems design. What will you be doing? • Design, troubleshoot, and optimize trading strategies and supporting pricing, risk management, and order execution modules • Iteratively improve trading models and parameters through research and data-focused analysis • Investigate new opportunities and avenues for firm market share growth or product expansion Skills and Experience: • At least one year professional experience in algorithmic trading, ideally equity or futures options • A track record of solving challenging analytical problems and implementing robust solutions • Firm understanding of statistics and probability, linear algebra, and calculus • Proficiency with Python and/or R for research, data analysis, and statistical modeling • Experience working with large datasets using relational databases, ideally SQL/MySQL • Exposure to Linux/Unix beneficial Annual base salary ranges from $150,000 to $200,000, and is influenced by a number of factors, including qualifications and experience. This role is also eligible for an annual discretionary bonus, of which can be a significant portion of total compensation. This full time role is also eligible for other forms of compensation and benefits including health/dental/vision insurance, and 401(k) contributions. Algorithmic Trader pay range $150,000 — $200,000 USD Why us? Founded in Chicago in 2004, Simplex is a leading, technology-driven, proprietary market-making firm. We work with the most advanced technology and software in the market, and we’ve continued to remain at the forefront of the industry by always focusing on innovation, automation, and data-driven analysis. We also leverage our experience and expertise to make strategic investments and capitalize on opportunities in the venture capital markets with promising, early-stage financial and technology start-ups.  PLUS, the goods! • Benefits: Excellent a la carte Medical/Dental/Vision (free employee coverage!), 401(k) match, generous parental leave! • The Office: The kitchen is stocked with snacks, and beverages; you also have daily stipends for breakfast and lunch!  • Tuition Reimbursement: As an investment in our employees’ careers and the company’s future, we offer educational assistance to provide employees with professional development opportunities that increase their skills and enhance their contributions to the organization! • Employee Discounts: To gyms, national brands, and more! • Building:  We are located in the Federal Reserve building. As a tenant, you have access to a building gym and a full cafeteria. We are easily accessible to all public transportation. • Charity Match: We match up to $2,000 a year in donations to the charities of your choice! • Fun Events: In-person happy hours, celebrations throughout the year, game nights, video game fun, and so much more! Simplex is an Equal Opportunity Employer. Simplex and its recruitment partners may use artificial intelligence (AI) tools to support certain aspects of the recruiting and hiring process. Final hiring decisions are made by humans. For all job postings, Simplex may use AI to review and analyze applications, resumes, interviews, and applicant responses.  Simplex complies with applicable federal and state laws governing AI use. Applicants may still request reasonable accommodations. For more information related to AI or to request an accommodation, please contact  HR@simplextrading.com . 

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