Ken Griffin founded the hedge fund Citadel in 1990 and is its chief executive and co-chief investment officer; he also founded and owns the market maker Citadel Securities.
Ken Griffin founded the hedge fund Citadel in 1990 and is its chief executive and co-chief investment officer; he also founded and owns the market maker Citadel Securities.
Griffin was born in Daytona Beach, Florida, in 1968 and grew up mainly in Boca Raton. He began trading convertible bonds from his dormitory at Harvard College, where he installed a satellite dish to receive stock quotes, and launched his first fund in 1987. He graduated with a degree in economics in 1989.
After a year trading for Frank Meyer's Glenwood Capital in Chicago, he started the firm that became Citadel in 1990 with $4.6 million; it was first called Wellington Financial Group, after its flagship fund, and took the Citadel name in 1994. In the early 2000s he founded Citadel Securities, now one of the largest US market makers. Citadel's largest funds lost about 55% in 2008, and the firm restricted withdrawals for ten months, then gained 62% in 2009; in 2022 the flagship Wellington fund returned 38.1%.
In 2022 Griffin moved Citadel's and Citadel Securities' headquarters from Chicago to Miami. He testified to Congress in 2021 about Citadel's role in the GameStop trading episode, and is a large donor to education, medical research and mostly Republican political causes.
Sources · written 23 October 2026