Jeff Yass

Jeffrey Yass is an American billionaire investor and co-founder of Susquehanna International Group (SIG), a Philadelphia-based quantitative trading firm renowned for its expertise in options market-making and proprietary trading strategies. As of October 2025, Yass holds a net worth of approximately $65.7 billion, making him one of the world's richest individuals and Pennsylvania's wealthiest resident.

Yass co-founded SIG in alongside college friends after honing skills in poker and options trading, drawing parallels between probabilistic decision-making in games and financial markets to build the firm's risk management framework. Under his leadership as managing director, SIG expanded from a niche options trader into a global powerhouse handling diverse assets, including equities, commodities, and cryptocurrencies, while maintaining a low public profile despite its scale.

Key to Yass's fortune are strategic investments, notably SIG's 15% stake in ByteDance, the parent company of TikTok, which significantly amplified his wealth amid the platform's growth and regulatory scrutiny. He has also pursued stakes in entities like Truth Social and crypto-related ventures, reflecting a pattern of high-conviction bets on undervalued or disruptive technologies.

A libertarian advocate, Yass serves as vice chairman of the Cato Institute and has emerged as one of the largest individual political donors in recent U.S. election cycles, contributing over $46 million in 2024 primarily to Republican-aligned groups focused on limited government, tax reform, and school choice initiatives. His philanthropy emphasizes educational vouchers and market-oriented policies, often channeling funds through organizations like Club for Growth to influence state-level reforms, such as opposing Pennsylvania's gambling tax expansions.