A Hedge-Fund Billionaire’s Two Bitter Wars—Against His Wife and His Business Partner
John Overdeck is trying to prevent a feud with his wife over his $723 million divorce settlement offer from costing him in a battle with his Two Sigma co-founder
Hedge-fund billionaire John Overdeck is facing a divorce trial with his wife Laura and a separate standoff with Two Sigma co-founder David Siegel.
Laura Overdeck is seeking a cash payment equal to 35% of her husband’s stake in Two Sigma, which her lawyers estimate is worth about $2.2 billion.
The State of Wisconsin Investment Board and the Public Employees Retirement Association of New Mexico have redeemed money from Two Sigma.
Hedge-fund billionaire John Overdeck is going through two acrimonious breakups at once.
One is a tabloid-worthy court battle with his estranged wife over whether the $723 million he has offered her is fair settlement for the dissolution of their nearly 24-year marriage. The other is a longer running and possibly nastier standoff with his co-founder at Two Sigma—an $85 billion quant-trading colossus—over the direction and control of the firm.
Sitting in the witness box in a New Jersey family court on Aug. 19, with his wife Laura watching him from a few yards away, Overdeck was trying to prevent the first battle from costing him the second.
Laura Overdeck’s lawyers were pressing the court to make public various confidential Two Sigma governance and financial records. John Overdeck, worried that any such release would supply ammunition to Two Sigma co-founder David Siegel in their battle, objected.
Judge Bruce Buechler sounded exasperated. The only reason he could conceive why Laura Overdeck wanted the information public, he said, was to pressure her husband for a better settlement. In court the following week, the judge noted: “The court is presiding over a divorce trial between Laura Overdeck and John Overdeck. It is not presiding over a trial between, by way of example, Dr. Siegel and Mr. Overdeck.”
Document disclosure or not, it won’t be easy for John Overdeck, 56 years old, to keep his two big problems from becoming one.
Overdeck and Siegel have clashed for years at Two Sigma—over executive roles and compensation, succession planning and other major issues. In the process, they have lost top talent and big clients.
His wife is seeking a cash payment equivalent to 35% of his stake in Two Sigma, or about $2.2 billion based on her lawyers’ estimate of the firm’s value. Being forced to liquidate that much of his stake to raise cash could tip control of the firm into Siegel’s favor. “Maintaining voting parity with Dr. Siegel is a principal concern,” Overdeck testified at his divorce trial last month.
A Two Sigma spokeswoman said the firm’s assets under management are at a record high, investor demand remains strong, and the current year’s performance ranks among its best. “We have been open with our investors about the disagreements between our co-founders and the resulting challenges,” she said.
Some investors, though, have had enough. Among the big clients that have pulled money out is Wisconsin’s pension fund, according to people familiar with the matter and disclosures reviewed by The Wall Street Journal.
Overdeck, a math prodigy who once worked at Amazon as Jeff Bezos’ technical assistant, and Siegel, a computer scientist with a Ph.D. from the Massachusetts Institute of Technology, co-founded Two Sigma in 2001. The pair had worked together in the 1990s at quant hedge-fund firm D.E. Shaw Group.
That was where John Overdeck met Laura. He proposed to her on the spring equinox of 2002, a few weeks before Two Sigma started investing with about $27 million in capital. By the time they married that October, Two Sigma’s assets under management had shot up to about $350 million.
Like other quant firms, Two Sigma programmed its computers to sift through oceans of stock prices and other data to find patterns that helped predict where markets would move. Overdeck presided over the team of quant researchers, or modelers, who designed blueprints for trades. Siegel’s engineers constructed the underlying systems that enabled those trades to happen.
At his divorce trial, Overdeck used a soccer analogy to describe the division of labor between Siegel and him. “I would liken the trading and modeling to the striker, or the guy who kicks the ball in the goal at the end of the play,” he said. “Investment management is very much a team sport. I was managing the very offensive end of the field.”
The co-CEOs tried to foster a culture of nerdy comity, pitching Two Sigma as the “best place for nice geeks to work.”
Laura Overdeck, who had a degree in astrophysics and an M.B.A., had stopped working to be a stay-at-home mom and author in Short Hills, N.J. The couple eventually had three children. Her husband later testified that he tried to stay involved, coaching the kids’ sports teams and limiting work on weekends.
At the office, under Two Sigma’s original operating agreement, Overdeck and Siegel needed to reach consensus on most decisions. For years, that didn’t matter much because the two got along well enough. Employees often spotted them having lunch at a Mexican restaurant near Two Sigma’s headquarters in Manhattan’s SoHo neighborhood.
Over time, though, they began to clash over decisions, and over who deserved credit and recognition for Two Sigma’s successes. Employees got used to walking on eggshells if there was a risk Overdeck and Siegel could perceive a slight, people familiar with the matter said. Planners of events agonized over which of the two should be asked to make opening or closing remarks, wondering if either would view one slot as inferior to the other, one of the people said.
When the Covid-19 pandemic hit, the relationship deteriorated further, former employees said. A lengthy work-from-home period allowed conflicts to fester. Overdeck’s team of modelers and Siegel’s team of engineers bickered over how the bonus pool would be divided and which group’s job openings would take priority among Two Sigma’s recruiters.
At home in New Jersey, the Overdecks’ nearly two-decade marriage was disintegrating. Laura Overdeck filed for divorce in March 2022, citing irreconcilable differences. The couple didn’t have a prenuptial agreement, and their split quickly became contentious.
At one point, Laura Overdeck accused her child’s fencing coach of being John Overdeck’s “paramour,” insinuating their relationship was a reason her marriage ended, according to a defamation lawsuit the fencing coach filed. Laura Overdeck didn’t respond before the lawsuit was dismissed.
The discovery process of the divorce case turned up evidence that Laura Overdeck didn’t disclose that she accessed files from John Overdeck’s computer sitting on a desk in their home and photographed some documents, Judge Buechler said at an April hearing. The judge cited that as one reason for not allowing her to testify or introduce her own witnesses in the divorce trial.
Laura Overdeck also contacted Siegel, hoping her lawyers could depose him, partly to try to show that her husband’s Two Sigma stake is worth more than he claimed. She sent him 700 pages of documents, including photographs from her husband’s computer, John Overdeck’s lawyers said in a June court filing.
Two-headed firm
Around 2022, Overdeck and some of his allies at Two Sigma, including general counsel Matt Siano, drafted a proposal for Siegel to step aside because the status quo was untenable, people familiar with the matter said. The document, which came to be known inside the firm as the “manifesto,” didn’t land well.
The manifesto intensified the discord atop Two Sigma, which by 2023 reached a boiling point. Overdeck and Siegel each needed to sign off on senior executives’ compensation, resulting in some bonus payments being held up.
The firm’s annual filing that year with the SEC cited the relationship between Overdeck and Siegel as a material risk. It said management couldn’t agree on a number of topics, including the leadership structure of various teams and the responsibilities for a range of C-suite executives.
Two Sigma’s filing said disagreements between Overdeck and Siegel affected the firm’s ability to retain and attract employees, including senior ones.
One trigger for the disclosure was an inability to agree on a replacement for operations chief Jonathan Hitchon, who retired in 2023 and served as a kind of diplomat between Overdeck and Siegel. After months of gridlock, Two Sigma named two interim co-COOs. Later, the firm named co-general counsels to succeed Siano.
In August 2024, Two Sigma announced that Overdeck and Siegel would cede their co-CEO roles while remaining the firm’s co-chairman. A two-person management committee would assume day-to-day responsibilities, with Overdeck and Siegel each appointing their own delegate.
Each of them chose a proxy who was seen as loyal. Overdeck picked Carter Lyons, an investor-relations executive who had been serving as Two Sigma’s chief business officer. Siegel chose Scott Hoffman, a former M&A lawyer. Lyons and Hoffman became co-CEOs.
The setup didn’t last long. Overdeck decided to appoint himself to the two-person management committee in March 2025, though Lyons remained co-CEO. Hoffman resigned about a year later, citing “ongoing governance challenges since Mr. Overdeck’s return,” according to a firm filing earlier this year.
Siegel designated Seth Platt, who served as chief investment officer of Siegel’s family office, to take Hoffman’s spot on the management committee—and accordingly serve as co-CEO, Platt believed. Platt, perceiving that Lyons undermined his authority, tried to fire Lyons. Overdeck invoked his right to move the dispute into a formal resolution process.
“Accordingly, whether Mr. Platt also will serve as co-CEO is in dispute,” Two Sigma said in a regulatory filing.
In August, Platt countered with a demand for arbitration, asking the panel to declare him the co-CEO, according to an investor letter reviewed by the Journal.
Siegel separately brought a new arbitration claim against Overdeck accusing him of breaching his fiduciary duty and having “undisclosed professional and financial conflicts of interest,” the investor letter said. At issue was Overdeck’s hiring of Siano as a consultant for his family office while Siano was in arbitration against Two Sigma over his deferred compensation and severance, according to the letter and people familiar with the matter.
Client concern
The increasingly public rift hasn’t led to an exodus of clients. One reason is that the funds continue to perform well. Two Sigma’s Absolute Return Enhanced fund gained about 16% this year through September, and the firm has raised about $4.5 billion in net new money this year, a person familiar with the matter said.
Another reason is that most investors can cash out monthly, making them comfortable sticking around. Also, most top quant funds are closed to new capital.
Some investors, though, have left. Overdeck testified in his divorce case that even though Two Sigma’s assets under management increased since his disputes with Siegel became known, they did cause redemptions.
The State of Wisconsin Investment Board, an agency overseeing more than $178 billion in assets that manages money for the state’s retirement system, fully redeemed from Two Sigma after the rift became public, according to the agency’s disclosures and people familiar with the matter. At the end of 2023, it disclosed over $1 billion invested in Two Sigma funds.
By the end of 2024, the pension plan of candy and snacks maker Mars Inc. redeemed about one-quarter of the roughly $70 million it had invested, according to disclosures reviewed by fund-data tracker Old Well Labs.
Earlier this year, Albourne, a hedge-fund gatekeeper that advises institutions where to invest their money, lowered its rating on Two Sigma, people familiar with the matter said.
This past summer, the Public Employees Retirement Association of New Mexico redeemed its entire investment of roughly $100 million from a Two Sigma fund. PERA, which manages retirement plans for about 100,000 active members and retirees across New Mexico, said at an August board meeting that “organizational concerns have created uncertainty and there is no credible resolution timeline,” according to the minutes of the meeting.
Two Sigma has been trying to stay out of the media spotlight on Overdeck’s divorce drama. “We recognize that recent media attention has extended to John Overdeck’s divorce trial, and we expect it to continue,” the firm said in its August letter to investors. “This is a personal matter and we are not a party to those proceedings.”
Overdeck testified in August that if private information about Two Sigma were to become public, he worried Siegel could take legal action against him for not fulfilling his confidentiality obligations to the firm. And more legal squabbles, he said, could make investors question the firm’s ability to operate as it has in the past.
“I am concerned that large investors in the company would consider reducing their investment…given the large volume of press and conflict,” he said.
His wife’s lawyers countered that divorce proceedings are supposed to be public.
In court earlier this month, an expert witness called by John Overdeck pegged the value of his stake in Two Sigma entities at about $50 million at the time of the marriage and roughly $4.5 billion around the time of the divorce filing.
Judge Buechler closed the courtroom to the public in the middle of his testimony. “It deals with projections and the information with regard to where the various Two Sigma entities are going, what they’re looking at, what they’re investing in, which is what I think some of the people sitting here are hoping they’ll get to hear,” he said.