Updated: September 1, 2026
John Overdeck, the math-minded co-founder of quant powerhouse Two Sigma, has spent recent months in a New Jersey courtroom fighting one of the most expensive divorce cases in state history. While the headlines focus on billions of dollars and the future of his stake in an $80 billion hedge fund, another name keeps surfacing: Lauren Phillips. The 40-year-old fencing coach has been publicly linked to the billionaire as his girlfriend, adding a personal layer to an already dramatic split.
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Who Is John Overdeck?
John Overdeck, 56, is a Stanford-trained mathematician and statistician who co-founded Two Sigma Investments in 2001 with David Siegel. The firm has grown into one of the most successful quantitative hedge funds in the world, managing more than $80 billion in assets. Overdeck’s net worth is estimated in the multi-billions, driven largely by his ownership stake in the firm.
He married Laura Bilodeau (now Laura Overdeck) in October 2002. The couple have three children and built a notable philanthropic presence through the Overdeck Family Foundation, which focuses on education and STEM programs. They lived in a large home in the Millburn/Short Hills area of New Jersey. Their marriage ended when Laura filed for divorce in early 2022 citing irreconcilable differences. Importantly, the couple never signed a prenuptial agreement.
The High-Stakes Divorce from Laura Overdeck
The divorce trial that began in August 2026 has become New Jersey’s largest contested matrimonial case. Laura Overdeck is seeking 35 percent of the value of John’s stake in Two Sigma, which her side values at roughly $6.2 billion. John’s side puts the stake closer to $4.9 billion and has offered a settlement in the $723 million range, which he has described in court as fair.
Key points of contention include:
- Whether the growth of Two Sigma after the 2002 marriage counts as a marital asset
- Control and funding of the family foundation
- Various trusts and other holdings
The case has already produced unusual twists, including a court ruling that barred Laura from testifying after findings related to discovery issues. John has taken the stand to defend his settlement offer and explain the firm’s history.
Introducing Lauren Phillips, the Fencing Coach Linked to Overdeck
Lauren Phillips is a 40-year-old award-winning former Rutgers University fencer who now runs her own fencing academy in Millburn, New Jersey. She has more than two decades of coaching experience and has trained students who went on to earn college scholarships and, in some cases, compete at high levels including the Olympics. One of the Overdeck children trained with her for about five years, creating a direct connection between the coach and the family.
In late 2024, Phillips filed a defamation lawsuit against Laura Overdeck. Court papers claim Laura publicly referred to Phillips as John’s “paramour,” blamed her for the marriage breakdown, and made other statements that Phillips said damaged her reputation and business. The suit described the comments as false and harmful to her professional relationships.
What We Know About Their Relationship
Police body-camera footage from 2023, later reported in the media, captured tense moments at the Overdecks’ New Jersey home. In one incident, John told officers he was in a “dating relationship” with a woman but insisted they had never been intimate or even undressed together. Laura, who arrived during the scene, referred to the woman as a “psycho girlfriend” and expressed concern about her involvement with the children.
Multiple 911 calls were made to the property involving the same woman between 2023 and 2024. The reports paint a picture of a complicated personal situation unfolding alongside the formal divorce proceedings. Phillips has not publicly detailed the nature of any relationship with John beyond the defamation claims she brought against Laura.
Quick Facts at a Glance Person Age Key Role / Background Connection to Case John Overdeck 56 Co-founder, Two Sigma Husband; defending settlement offer Laura Overdeck 56 Education advocate, Bedtime Math founder Wife seeking major share of assets Lauren Phillips 40 Fencing coach, former Rutgers athlete Alleged girlfriend; filed defamation suit Two Sigma — Quant hedge fund managing ~$80B Central asset in dispute
Conclusion
John Overdeck’s personal life has become inseparable from one of the most closely watched divorce cases of 2026. While the court battle centers on money, ownership, and the future of a major Wall Street firm, the presence of Lauren Phillips has added an emotional and public dimension that few expected. As the trial continues, both the financial outcome and the private relationships involved will remain under scrutiny. For now, the fencing coach remains the most visible figure linked to Overdeck outside his long marriage, reminding everyone that even billion-dollar splits often include very human complications.