The Most Important Firm You’ve Never Heard Of - Part 3

If you have not yet read Part 1 and Part 2 of this topic, please do so before continuing here.

The Other Controversies

The SEBI case isn't the only one Jane Street is currently navigating. In June 2025, co-founder Robert Granieri was named in the federal indictment of Peter Ajak and Abraham Keech, two men accused of conspiring to illegally export weapons in support of an alleged coup attempt in South Sudan. Court filings disclosed that Granieri had personally funded $7 million towards the plot, money that was used to acquire Stinger missiles, grenade launchers, machine guns, and over 3.5 million rounds of ammunition. Granieri's defense was that he'd been duped and believed he was supporting a humanitarian effort. No charges were brought against him personally. Ajak and Keech were sentenced to 3.5 years in prison.

In February 2026, the post-bankruptcy manager of Terraform Labs filed a lawsuit in the Southern District of New York alleging that Jane Street "abused market relationships to rig the market in its favor" in trades that contributed to Terraform's 2022 collapse. Jane Street has denied wrongdoing and filed a motion to dismiss in April 2026.

These are very different situations. One is a personal matter involving a co-founder and a humanitarian story he says he was tricked into. One is a civil lawsuit from a bankrupt counterparty. One is a regulatory investigation by a major sovereign market regulator. None of them, individually, would meaningfully threaten the firm. Together, they form a pattern: when a firm gets large enough and quiet enough, scrutiny eventually finds it.

Why This Firm Matters More Than You Think

The temptation with a profile like this is to treat Jane Street as a curiosity. A weird private firm with a lot of money, an OCaml fetish, and a famous alum in federal prison. That undersells it. Consider what Jane Street actually does in markets:

• It is a foundational liquidity provider for ETFs, holding 24% of the primary US-listed ETF market and 41% of bond ETF volume. The growth of passive investing globally runs through firms like Jane Street.
• It accounts for around 10% of North American equity volume and 8% of US options volume. Price discovery in the deepest markets in the world is partly a function of Jane Street's models.
• It is now a meaningful AI compute buyer through CoreWeave and a meaningful AI lab investor through Anthropic. The firm's capital is increasingly upstream of the AI infrastructure that's reshaping the economy.
• It has shaped derivatives microstructure in markets as different as the US, Europe, and India, in ways that regulators are only now starting to investigate.

And it does all of this with a workforce smaller than a single trading floor at a large bank, a comp model that pays like top-tier private equity, and a public profile so quiet that most retail investors have never encountered the name. That's not an accident. It's the model. Jane Street has built a firm that benefits enormously from being uninteresting to the public and indispensable to the plumbing. The interesting question for the next decade isn't whether Jane Street keeps growing. It's whether anyone (regulators, competitors, or the firm itself) can keep up with what it's becoming.

The most important firm in markets right now is one most readers couldn't have named an hour ago. By the time the average investor knows the name, Jane Street will probably already be something else.

*This article is for informational and educational purposes only. It is not investment advice, a recommendation, or a solicitation to buy or sell any security. All allegations referenced in this article remain subject to ongoing legal and regulatory proceedings. Arbitrage Trade has no affiliation with Jane Street Group, LLC or any of its entities.