John Albert Overdeck (born 1969) is an American billionaire hedge fund manager best known as the co-founder and co-chairman of Two Sigma Investments, a New York-based firm that leverages artificial intelligence, machine learning, and distributed computing for its trading strategies, managing $41 billion in assets as of May 2017. A mathematical prodigy, Overdeck won a silver medal at the 1986 International Mathematics Olympiad and holds degrees from Stanford, later working at D.E. Shaw and Amazon before launching Two Sigma in 2001 with David Siegel. His success has made him one of the highest-earning hedge fund managers, with a net worth of $6.1 billion in March 2019, ranking 9th on Forbes' list in 2017. Beyond finance, he is deeply involved in philanthropy, co-founding the Overdeck Family Foundation in 2011 with his wife Laura to fund STEM education, and serves as acting chair of the National Museum of Mathematics. In his personal life, Overdeck married Laura Bilodeau in 2002, but she filed for divorce in 2022 citing irreconcilable differences, leading to a legal dispute over assets without a prenuptial agreement.