Someone with knowledge of the situation, who asked not to be named because the process is private, said that Seth Platt asked David Siegel to start looking for a replacement to serve as his delegate on Two Sigma's management committee, and that he plans to leave the firm once that person is selected. Two Sigma manages about $85 billion.
In a statement, the firm praised its people and platform "built over decades" as the base for "long-term success," adding, "Our team is focused on delivering for our investors, with 2026 shaping up to be one of the strongest years in Two Sigma's history." Separately, the Absolute Return Enhanced Fund gained 16% this year through September, according to a person familiar.
Platt's likely departure follows months of debate over whether he should also hold the co-CEO title. Tensions between co-founders David Siegel and John Overdeck, who launched Two Sigma in 2001, had grown to the point that the firm flagged the rift in a March 2023 regulatory filing as a material risk.
In 2024, both founders relinquished the co-CEO titles and departed the management committee. Overdeck selected then-13-year firm veteran Carter Lyons to act as his stand-in for both positions; Siegel, meanwhile, named Scott Hoffman, formerly Lazard's general counsel. After eight months, Overdeck rejoined the management committee, displacing Lyons from that seat but keeping him as co-CEO.
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Two Sigma disclosed in a March 2026 filing that Hoffman had resigned, citing "ongoing governance challenges" since Overdeck rejoined the committee. Siegel then appointed Platt to fill Hoffman's committee spot, and since then the founders have been at odds over whether Platt should automatically be made co-CEO alongside Lyons.
After he leaves Two Sigma, Platt plans to continue at Siegel's family office, taking the CIO and COO posts. According to the family office, speaking through a representative, Siegel has no plans to return to day-to-day management of the hedge fund, noting, "He remains focused on his philanthropy, serving as an Innovation Fellow at MIT, and publishing his first book." The spokesperson added, "Following Seth's request to be replaced as Executive Manager designee, a search process was initiated to identify a successor to manage Two Sigma alongside John."
Why it matters: leadership clarity can shape strategy, risk controls, and investor confidence. For now, the governance tug-of-war sits next to performance data like the 16 percent year-to-date gain in the Absolute Return Enhanced Fund through September.
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