John Albert Overdeck (born 1969) is an American hedge fund manager and philanthropist. Overdeck is the co-founder and co-chairman of Two Sigma Investments, a New York City-based hedge fund that uses a variety of technological methods, including artificial intelligence, machine learning, and distributed computing, for its trading strategies. In 2016, Overdeck reported $375 million in earnings and as of May 2017, Two Sigma Investments has $41 billion in assets under management. In March 2019, he was named one of the highest-earning hedge fund managers and traders by Forbes.