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Simplex Overview

Headquarters Chicago, IL
Size 51 to 200 Employees
Founded 2004
Type Company - Private
Industry Finance
Simplex Investments is a growing, Chicago-based proprietary trading firm that leverages capital, trading intelligence, and exceptional technological resources in a dynamic, results-driven atmosphere with a focus on innovation and learning.

Company Updates

  • Want to look at raw exchange data? Want some test data for your low latency order book? http://glassdoor.com/slink.htm?key=vIpNZ

  • Would you have made these optimizations? Come work at Simplex. http://glassdoor.com/slink.htm?key=vIKWk

    How does grep run so fast?

    To add to Steve's excellent answer. It may not be widely known but grep is almost always when grepping for a pattern-string than a short one, because in a longer pattern, Boyer-Moore can skip forward in longer strides to achieve even better speeds: Example: # after running these twice to ensure apples-to-apples comparison # (everything is in the buffer cache) $ time grep -c 'tg=f_c' 20140910.log 28 0.168u 0.068s 0:00.26 $ time grep -c ' /cc/merchant.json tg=f_c' 20140910.log 28 0.100u 0.056s 0:00.17 The longer form is 35% faster!

Simplex – Why Work For Us?


Simplex offers an unparallel work environment dedicated to technological advancement and superior trading techniques. Our workforce is comprised of a diverse group of innovative developers, driven traders and in-house supportive staff.  We have strong appreciation for a variety of backgrounds and welcome creative problem solving and passionate individuals. At Simplex, we recognize the efforts and commitment of each of our employees and offer competitive compensation and benefits.


Our talented group of developers is constantly striving to meet new and demanding challenges through the use of creative problem solving and software development.  We research, design, develop and test all software applications for in house trading purposes. Our developers have an unmatched knack for resourceful thinking and a passion for innovative technological development.


Simplex uses individual trading strategies to best recognize and enhance market profitability. We pride ourselves on safe trading policies and the ability to identify opportunities in the financial markets. Our driven traders possess superior analytical skills and thorough understanding of algorithmic trading.   


Simplex has an incredible industry edge due to its technological infrastructure and in-house technical support department. We strive to continually automate, innovate and optimize the trading processes through the use of technology. Our team applies the many facets of technology to further solidify the relationship between trading profitability and innovative development.


We work closely with our founders in an effort to maintain our focus and achieve company goals. Our highly regarded leadership offers exclusive insight and guidance to each of our employees further maximizing capital and potential.

Simplex stresses an adequate work life balance and encourages our employees to participate in company sponsored events and other non work related activities. It is important for each team member to have sense of life outside of the job for better productivity and company morale.

Simplex is a host of brilliant minded individuals honing and sharing their expertise of technology and trading. We are staunchly committed to excellence and strive to improve our accomplishments on a daily basis. Our claims are substantiated by our long term profitability, market sustainability and proven success.

Simplex Reviews

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Erik Swanson
6 Ratings
  • Featured Review

    Helpful (4)

    a good place for talented hackers

    • Work/Life Balance
    • Culture & Values
    • Career Opportunities
    • Comp & Benefits
    • Senior Management
    Current Employee - Software Developer in Chicago, IL
    Current Employee - Software Developer in Chicago, IL
    Positive Outlook
    Approves of CEO

    I have been working at Simplex full-time (More than 5 years)


    Developers get to take ownership of their projects and can get recognized for their contributions. The company has a very flat hierarchy and offers a lot of opportunities for developers to work on interesting projects where code latency really matters. Most of the developers at the company are genuine hackers and are passionate about their work. Also the benefits and compensation are great.


    Like most jobs in this industry, it can be stressful at times but that keeps things interesting. Being a smaller company, there is limited formal training for new hires, but you learn by performing smaller development tasks and working your way up. There are no separate QA or operations teams. As a result the developers are responsible for those duties as well.

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Simplex Interviews

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Interview Experience


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Getting an Interview


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Interview Difficulty



  1. Helpful (1)  

    Junior Trader Interview

    Anonymous Interview Candidate in Chicago, IL
    No Offer
    Neutral Experience
    Difficult Interview


    I applied online. The process took 2 weeks. I interviewed at Simplex (Chicago, IL) in February 2012.


    I had to take a longer wonderlic and then one and a half hour long test on brain teaser problems, solving derivatives, creating confidence intervals, and very basic options problems..if you dont score high enough they make you leave..if you score high enough you do a group project and they pick from there

    Interview Questions

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