Ken Griffin

Ken Griffin is the most prolific Republican donor in Wall Street history — over $350 million in career political spending — and the head of Citadel, one of the most powerful financial institutions in the world. His donations flow to politicians who share one common position: opposition to financial regulation. Specifically, opposition to regulating payment for order flow, the practice by which Citadel Securities — Griffin's market-making arm — earns billions by routing retail stock trades. Griffin was born in Daytona Beach, Florida in 1968. A prodigy, he began trading from his Harvard dorm room in 1987 using a satellite dish on the roof to get real-time stock quotes. He founded Citadel in 1990 at age 22 with $4.6 million. The firm grew into a $60 billion hedge fund and, through Citadel Securities, one of the largest market makers in the world. Citadel Securities handles roughly 40% of all U.S. retail stock trades through payment for order flow — meaning that when ordinary Americans buy or sell stocks through apps like Robinhood, Citadel Securities often executes those trades and profits from the spread. This business model became the center of national controversy during the January 2021 GameStop saga, when retail traders organized on Reddit to short squeeze hedge funds. Robinhood restricted trading in GameStop, and Citadel's relationship with Robinhood (Citadel Securities was Robinhood's largest revenue source through PFOF) led to conspiracy theories and Congressional hearings. Griffin testified before Congress, denying any involvement in Robinhood's decision. The episode accelerated his political spending. In 2022, he donated $60 million to Republican candidates — making him the third-largest donor that cycle. In 2024, he gave approximately $100 million, primarily through the Senate Leadership Fund and Congressional Leadership Fund. His giving spans the full GOP ecosystem: senators, House members, governors, and state-level races. Griffin's political targets are consistent: every recipient opposes SEC regulation of payment for order flow, supports financial deregulation broadly, and resists the kind of market-structure reforms that could threaten Citadel's business model. When SEC Chair Gary Gensler proposed PFOF reforms in 2022, every senator who had received Griffin money opposed them. In 2022, Griffin spent $50 million in a failed attempt to defeat Illinois Governor J.B. Pritzker. After losing, he moved Citadel's headquarters from Chicago to Miami — a dramatic statement of political pique that also happened to save him Florida's zero state income tax. The move was widely interpreted as both revenge against Illinois Democrats and a financial optimization. Griffin's philanthropy is substantial — hundreds of millions to museums, universities, and cultural institutions, including a $150 million gift to Harvard. But the philanthropy doesn't erase the math: Citadel Securities' PFOF business generates billions annually, and every dollar Griffin spends on politics protects that revenue stream. At $350 million in career giving versus billions in PFOF revenue, the ROI is astronomical.