E dward Netylko is an American investor and a key early partner at Susquehanna International Group (SIG), one of the world's largest and most secretive quantitative trading firms. SIG was founded by a group of friends who were expert poker players, and they applied the same principles of game theory and statistical analysis to the financial markets, particularly options trading.

Netylko has been a central figure at the firm for decades, contributing to its growth into a global market-making and proprietary trading powerhouse. He is part of the small group of partners who have run the firm since its early days. His immense wealth is derived from his ownership stake in the highly profitable and privately held firm. Like the other founders and partners of SIG, he maintains an extremely low public profile, consistent with the firm's secretive culture.