Jane Street Brand Guidelines: A Street Name Picked at Random, OCaml and a Puzzles Page

Four founders, foreign shares and a borrowed name.

Jane Street is a trading firm in New York. English Wikipedia says it was co-founded in 1999 by Tim Reynolds, Robert Granieri, Marc Gerstein and Michael Jenkins; the firm’s own website refers to “our founding in 2000,” so both dates are given here. Three of the founders had been traders at Susquehanna International Group and Gerstein had been a developer at IBM, Wikipedia says.

The name does not belong to a person. According to Wikipedia, the founders chose Jane Street, a short street in Greenwich Village, more or less at random, and the company has never had its headquarters there. Its head office today is in Lower Manhattan’s Financial District, the first address on the firm’s contact page.

The firm started by trading American depositary receipts, the US-listed shares of foreign companies, and then moved into exchange-traded funds, which became its main focus, Wikipedia says; through the late 2000s it added fixed income, futures, commodities and equity options. The company says it “became known for its expertise in domestic and international ETFs” and that its trading “has grown significantly since our early days,” with equities, bonds and options now among its main markets. It says it trades continuously on more than 200 electronic exchanges and other venues.

Its organisation is unusual for a firm of its size. Wikipedia describes leadership by an informal group of 30 or 40 senior people, with no chief executive, and pay tied to the firm’s collective results rather than to individual trading gains. It puts the staff at about 3,000.

OCaml, machine learning and five trading floors.

Technology is central to how Jane Street describes itself. Its home page calls it “a research-driven trading firm where curious people work together on deep problems,” under the line “Solving the puzzle of global markets,” and its technology page speaks of low-latency networks, compilers and distributed systems. Wikipedia says the firm uses the programming language OCaml for its operations and contributes open-source libraries, including work on an OCaml compiler, alongside growing use of Python for machine learning. The OCaml project’s own website carries a quote from Yaron Minsky, named there as Jane Street’s chief technology officer, saying that “billions of dollars of transactions flow through our systems every day.” Interns, the firm’s internship page says, can learn why Jane Street uses OCaml.

Machine learning is the second theme. The company says it has used “a variety of modeling techniques since our founding,” and its home page says it believes deep learning is the future of quantitative trading. In November 2020 it opened a public market-prediction competition built on its own trading data, which ran until August 2021, Wikipedia says; researchers have since used that dataset in studies of trading decisions.

The firm presents itself through puzzles as much as through finance. Its Puzzles page posts a new problem “every month or two” and explains that puzzle solving “is intrinsic to the work we do,” before noting that the page itself is a puzzle. The website also links to a podcast and a technology blog, and lists events described as meet-ups “with puzzles, tech talks, games, and more.” Its internships usually run for 10 to 12 weeks between May and September in New York, London and Hong Kong, the company says, adding that many of its people do not come from a financial background.

The trading floors are spread across five cities. The company names New York, London, Hong Kong, Singapore and Amsterdam, and says that standing on a Jane Street trading floor “feels like being at the center of something much bigger.” Its European and Asian businesses are run by separate regulated subsidiaries, each wholly owned by Jane Street Group, LLC, the website’s legal notice says.

How trading firms present themselves.

Proprietary trading firms and electronic market makers sell little to the public, so their identities are built for a narrow audience: the students, engineers and researchers they hope to hire, and the institutions they trade with. Their websites read less like consumer marketing and more like careers sites, with pages on departments, open roles, interviewing and benefits placed as prominently as any description of the business.

Recruiting shapes the tone. Jane Street, for example, keeps a Puzzles page that posts a new problem every month or two, and its events include meet-ups built around puzzles and technical talks. Coding challenges, internship programmes and scholarships do similar work, signalling that the firm values problem solving before it values a finance background.

The trading floor is the other recurring image. Firms describe offices in several financial centres and present their floors as places of shared work rather than private desks, while technology pages talk about low-latency networks, compilers and research. Blogs and podcasts carry much of the explanation, letting engineers and researchers speak for the firm instead of an advertising campaign.

The marks themselves tend to be modest: a plain name, a simple geometric symbol or a word set in capitals, used consistently across careers pages, legal notices and the regulated subsidiaries that carry the brand in each market. For designers, the category is a study in restraint, where credibility comes from clarity, consistency and a careful choice of tone rather than from colour or spectacle. The palettes in these guides are our own unofficial interpretations.

A concentric circle, a plain name and a case under appeal.

The visual identity is quiet. The website’s legal notice says that “Jane Street and the concentric circle mark” are registered trademarks of the firm.

The firm has also spent time in court. In June 2022 Jane Street and Elliott Investment Management sued the London Metal Exchange over the cancellation of nickel trades; the High Court dismissed the case in November 2023 and an appeal was rejected in October 2024, Wikipedia says. A lawsuit Jane Street brought against two former employees who had joined Millennium Management, over alleged use of its trade secrets, was settled in December 2024.

In India, the Securities and Exchange Board of India (SEBI) issued an ex-parte interim order in July 2025 that barred Jane Street from the Indian securities market over alleged manipulation of the Bank Nifty index, Mint reported; Jane Street denied wrongdoing and called its trades index arbitrage, Wikipedia says. SEBI allowed the firm to resume trading on 21 July 2025 after it made a deposit into an escrow account, the Press Trust of India reported in ET LegalWorld, while its investigation continued. Jane Street appealed to the Securities Appellate Tribunal, where the two sides argued in October 2026 over the firm’s request for more of the regulator’s documents, The Hindu BusinessLine and Mint reported; the tribunal reserved its order on that request, and the appeal had not been decided at the time of writing.

For a design guide, Jane Street shows a trading firm that speaks to the public mainly through puzzles, code and internship pages, under a registered concentric circle mark. Compare Virtu, the New York market maker listed on Nasdaq, and Susquehanna, where three of the founders traded. For this guide we use harbour navy, chalk white and a muted puzzle teal with a serif, an unofficial interpretation; no product or logo is reproduced.

Keep Jane Street’s identity on hand — save it to a board in the Made Good inspiration library.