How David built the fortune
Siegel's wealth comes from his ownership stake in Two Sigma, the quantitative investment manager he started in 2001 with John Overdeck. The firm's founding idea was that investing could be treated as a scientific and engineering problem. Rather than relying mainly on the judgment of individual stock pickers, Two Sigma builds statistical models, feeds them very large amounts of market and alternative data, and lets software execute trades across global markets. Siegel, a computer scientist by training, shaped much of the firm's technology culture and its emphasis on hiring researchers and engineers rather than traditional finance staff.
The business grew steadily through the 2000s and 2010s, attracting pension funds, endowments, sovereign investors and other institutions. As assets under management increased, so did the management and performance fees that flow to the firm and its owners. Because Two Sigma is privately held, the value of Siegel's share is not set by a stock market, and outside estimates depend on assumptions about the firm's profits and the returns of its funds.
In 2022 Siegel and Overdeck stepped back as co-chief executives and handed day to day leadership to a management committee, while remaining involved at board level. The partnership between the two founders had come under public strain in the preceding years, and the change was presented as a move toward a more institutional leadership structure.
Companies and holdings
Two Sigma has expanded beyond its flagship hedge funds into several related businesses over the years:
- Two Sigma Investments, the core manager running systematic strategies across equities, futures and other assets
- Two Sigma Securities, a market making and trading operation
- Two Sigma Ventures, which invests in early stage technology companies
- Two Sigma Impact, a private equity arm focused on companies that commit to improving conditions for their workers
Beyond the firm, Siegel holds a range of personal investments and has been an early supporter of education technology projects. Much of his public activity outside finance runs through the Siegel Family Endowment, which he set up with his family, rather than through a separate holding company.
Early life and career
Siegel was born in 1961 and studied at Princeton University, where he earned an undergraduate degree. He went on to the Massachusetts Institute of Technology and completed a doctorate in computer science, working in the area of artificial intelligence and machine learning at a time when those fields were still largely academic. His training in how computers can learn patterns from data would later become the intellectual base of Two Sigma's approach.
After leaving academia he moved into finance, joining D. E. Shaw, one of the early firms to apply computing power to trading. He later worked at Tudor Investment Corporation, where he helped develop computer driven trading strategies. At D. E. Shaw he crossed paths with John Overdeck, a mathematician, and the two eventually decided to build a firm of their own around the same principles. They launched Two Sigma in New York in 2001, giving it a name taken from statistics.
Philanthropy and public life
Siegel's main philanthropic vehicle is the Siegel Family Endowment, founded in 2011. It funds work on learning, the future of work and the physical and digital infrastructure of cities, and it often supports research and nonprofit programs that try to understand how technology changes society. He is also a cofounder and chair of the Scratch Foundation, which supports Scratch, the free programming language and online community created at the MIT Media Lab to teach children to code. Through these organizations he has backed computer science education in schools and broader efforts to widen access to technical skills.
He writes and speaks occasionally on artificial intelligence, data and the limits of prediction, often arguing for careful, evidence based use of new tools. He has served on boards of educational and cultural institutions in New York. He keeps a relatively low personal profile for someone with his wealth, and public attention on him has mostly come through Two Sigma's performance and leadership changes rather than through his private life.