Two Sigma Investments’ billionaire co-founder John Overdeck schemed to leave his wife Laura “with as little as possible,” her lawyer said as the couple’s divorce trial began, an amount she pegged at $633 million. The trial, unfolding in a New York court, has drawn attention to the vast wealth of the hedge fund firm’s leadership. Laura Overdeck’s attorney argued that the offer was a fraction of what she is entitled to, given the couple’s decades-long marriage and John Overdeck’s astronomical earnings from Two Sigma.

John Overdeck co-founded Two Sigma in 2001, and his net worth is estimated at over $5 billion, according to the Bloomberg Billionaires Index. Laura Overdeck, a philanthropist and former mathematics student, played a key role in their family foundation. The legal battle focuses on whether the prenuptial agreement signed years earlier is valid or was drafted under unfair conditions. Her lawyer claims the proposed settlement would leave her financially stranded.

The trial is expected to last several weeks, with both sides presenting experts on asset valuation and marital contributions. A judge will ultimately decide the fair distribution, a decision that could set a precedent for high-net-worth divorces in the financial industry.