Building a Trading Business or Career

In May 1987 a group of friends who had met at the State University of New York at Binghamton in the late 1970s, and who had spent a good part of the years since playing cards, started an options-trading operation on the floor of the Philadelphia Stock Exchange. Jeff Yass, the best known, had spent years on poker and racetrack betting before trading options (his own account in interviews). With Arthur Dantchik and their partners he called the firm Susquehanna, and built it on one idea: trading is a game of decisions under uncertainty, in which the right choice can lose and the wrong choice can win any single hand, and the only thing worth judging is the decision. Its first year included Black Monday. Nearly four decades later Susquehanna International Group is one of the largest options and ETF market makers in the world, and press reports say new hires are still expected to play at least about 100 hours of poker as part of a training programme that mixes probability, game theory and decision science with trading simulations (reported). It has never raised outside equity and publishes no financial statements (companion's profile of Susquehanna).

Its most consequential export was people. In 1999–2000 three Susquehanna traders, Tim Reynolds, Robert Granieri and Michael Jenkins, with Marc Gerstein, a developer from IBM, set up Jane Street to arbitrage ADRs and ETFs; Delaware records give an incorporation date of 31 August 1999, and the firm dates itself to 2000. It has no chief executive and pays staff from the firm's collective profits. By 2025 it reportedly earned about $39.6 billion of net trading revenue, a record that reportedly included gains from revaluing private stakes, among them Anthropic (Reuters, April 2026, from documents and anonymous sources; the firm did not confirm). Both are partnerships trading their own capital.

At the other end of the industry, on 29 August 2023, the CFTC sued a Canadian company, Traders Global Group, which sold evaluations under the name My Forex Funds. The agency alleged that more than 135,000 customers had signed up from November 2021 and paid at least $310 million in fees to trade simulated accounts under rules for a chance at a "funded" account; that the firm, not a third party, was the counterparty to substantially all their trades; and that it used software to fill orders at worse prices than customers saw. The case collapsed. On 13 May 2025 the federal court in New Jersey dismissed it with prejudice and sanctioned the CFTC for its own conduct in the litigation. The allegations were never proven, and this book treats them as allegations. Even as an allegation, the complaint shows the scale of a business paid by traders' fees rather than by trading (Chapter 19).