Key Takeaways
- • Alex Ginsburg, 21-year Two Sigma veteran and chief investment officer of equities research, has taken medical leave from the $60 billion quant hedge fund, with the announcement made to investors and employees in mid-July 2023.
- • Ali-Milan Nekmouche, the firm's chief data strategist since 2004, has been named as Ginsburg's replacement, while Jeff Penney and Timothy Reynolds were appointed as interim co-chief operating officers.
- • Ginsburg's departure follows a June 2022 incident in which he and other senior executives, including CIO Geoffrey Duncombe, threatened to resign if co-founder David Siegel did not step back from the firm—a threat they ultimately did not execute.
- • Two Sigma's leadership is fractured by a documented power struggle between co-founders David Siegel and John Overdeck over corporate governance, succession planning, executive roles, and organizational structure, with the firm disclosing these governance risks to investors in a March securities filing.
- • The personnel changes at Two Sigma compound broader concerns about executive retention and organizational stability at a firm managing $60 billion in assets, with management explicitly warning investors that founder infighting threatens recruiting, retention, and operational effectiveness.
Summary
Alex Ginsburg, a 21-year veteran at Two Sigma and the hedge fund's chief investment officer for equities research, has taken a medical leave of absence from the firm. Two Sigma notified its investors and announced the departure internally in mid-July 2023, according to sources familiar with the matter. Ginsburg's role has been assumed by Ali-Milan Nekmouche, the firm's chief data strategist who joined Two Sigma in 2004. The company has not publicly identified a successor to Nekmouche's previous position.
The announcement of Ginsburg's leave coincided with additional organizational changes, including the appointment of Jeff Penney and Timothy Reynolds as interim co-chief operating officers, signaling broader management transitions at the $60 billion quantitative trading firm.
Ginsburg's departure arrives during a particularly turbulent period for Two Sigma, as the firm grapples with a protracted power struggle between co-founders David Siegel and John Overdeck. In a March 2023 securities filing, Two Sigma disclosed to investors the risks posed by the founders' inability to agree on critical business matters, including corporate governance, succession planning, executive role definitions, and organizational structure. Management explicitly warned that the infighting threatens the firm's ability to recruit and retain talent, as well as employees' capacity to perform their jobs effectively.
The tension between Siegel and Overdeck has a documented history. According to the Wall Street Journal in June 2023, Ginsburg and Geoffrey Duncombe, another chief investment officer at Two Sigma, were among a group of executives who threatened to resign in 2022 if Siegel did not step back from the firm. Siegel remained in his position, and the group ultimately did not follow through on their threat to leave. Ginsburg's subsequent medical leave, however, underscores the ongoing challenges facing senior leadership at the hedge fund as internal governance disputes persist.
The announcement of Ginsburg's leave coincided with additional organizational changes, including the appointment of Jeff Penney and Timothy Reynolds as interim co-chief operating officers, signaling broader management transitions at the $60 billion quantitative trading firm.
Ginsburg's departure arrives during a particularly turbulent period for Two Sigma, as the firm grapples with a protracted power struggle between co-founders David Siegel and John Overdeck. In a March 2023 securities filing, Two Sigma disclosed to investors the risks posed by the founders' inability to agree on critical business matters, including corporate governance, succession planning, executive role definitions, and organizational structure. Management explicitly warned that the infighting threatens the firm's ability to recruit and retain talent, as well as employees' capacity to perform their jobs effectively.
The tension between Siegel and Overdeck has a documented history. According to the Wall Street Journal in June 2023, Ginsburg and Geoffrey Duncombe, another chief investment officer at Two Sigma, were among a group of executives who threatened to resign in 2022 if Siegel did not step back from the firm. Siegel remained in his position, and the group ultimately did not follow through on their threat to leave. Ginsburg's subsequent medical leave, however, underscores the ongoing challenges facing senior leadership at the hedge fund as internal governance disputes persist.
Go deeper than the headline
Research every firm in this story, track the ones that matter and get the daily briefing — free for 7 days.