Jeff Yass

Jeff Yass studied at Binghamton University and became an accomplished poker player, developing the probabilistic thinking and risk management instincts that would define his approach to options trading. In 1987, with $4 million in capital, he co-founded Susquehanna International Group (SIG) with four colleagues, including Arthur Dantchik and Joel Greenberg. SIG's founding philosophy was that options market-making is fundamentally a game of probabilistic edge — similar to poker — and that traders who deeply understand probability, game theory, and risk management can build consistent edge across thousands of small trades. The firm trained its traders extensively in poker and game theory before exposing them to markets, a pedagogical philosophy that became central to SIG's culture. This approach proved extraordinarily effective: SIG grew to become one of the world's dominant options market makers, making two-sided markets in millions of options contracts daily across global exchanges. The firm also expanded into equity market-making, ETF arbitrage, and proprietary trading. SIG is estimated to manage over $50 billion in trading capital. Yass is also a notable early-stage investor in technology companies: SIG was an early investor in ByteDance — the parent company of TikTok — at a valuation of approximately $50 million, an investment now worth many billions. He is known as an extremely private individual who rarely appears publicly but whose firm has shaped the global options market.