David Mitchell Magerman (born 1968) is an American computer scientist, philanthropist, former hedge fund executive, and tech entrepreneur. He earned a bachelor's degree in computer science and linguistics from the University of Pennsylvania in 1990. Magerman began his career in computational linguistics before co-founding and joining Renaissance Technologies in 1996, where he spent 22 years as a key figure in the quantitative hedge fund's operations, rising to senior vice president of investments and contributing to algorithmic trading strategies using natural language processing and data analysis. In 2018, he left Renaissance Technologies following a public fallout after criticizing then-President Donald Trump in a Washington Post op-ed, which strained his relationship with the firm's leadership. Post-departure, he founded Differential Ventures, a venture capital firm focused on early-stage tech investments in AI and biotech, and maintains ties to the Israeli tech sector. Magerman is known as a major philanthropist with significant involvement in Jewish and pro-Israel causes, serving as a board member and former chairman of Friends of the Israel Defense Forces (FIDF) until resigning in 2019 amid controversy over the organization's direction. He has donated millions to organizations supporting Jewish education, community welfare, and Israeli defense, including as a major donor to the University of Pennsylvania. He has been vocal on issues of democracy, Jewish identity, and technology ethics, funding initiatives at institutions like the University of Pennsylvania and various nonprofits. He publicly criticized the university's handling of antisemitism and threatened to withhold donations, contributing to pressure on President Liz Magill.