Billionaire John Arnold funds $2.6 million study into the health risks of sports betting

Arnold Ventures, the foundation run by billionaire John Arnold and his wife, Laura, has awarded roughly $2.6 million in research grants to 12 universities and think tanks examining what online sports betting is doing to the people who use it.

The foundation announced the grants Tuesday. The projects sit at institutions including Princeton, the University of Pennsylvania and the University of Wisconsin, and will study how gambling affects financial wellbeing, household formation, mental health and consumer behaviour. Some will also look at what regulators can do to limit the damage.

The reasoning is that the industry outran the evidence. Sports betting spread across the United States at speed, a foundation spokeswoman said, while policymakers were left without rigorous causal research on its effects or on which regulatory approaches actually work. The grants are meant to close that gap.

Arnold has singled out the phone as the change that mattered. Betting from a handset, he has argued, widened access and stripped away the friction that once slowed gamblers down. A bettor can now stake money on a single pitch, at a speed that was impossible when placing a wager meant ringing a bookmaker.

Justin Milner, the foundation's executive vice president of evidence and evaluation, put it more bluntly. "Anyone with a smartphone could effectively have a casino in their pocket," he said.

The industry's expansion traces to a 2018 Supreme Court ruling that struck down the federal ban and left legalisation to the states. Many moved within months.

Arnold has attributed the rush to money. State legislatures were drawn to the tax revenue on offer, he has said, and there is obvious appeal in collecting what amounts to a voluntary tax rather than a compulsory one.

One gap in the research programme stands out. None of the 12 studies will examine prediction markets such as Kalshi and Polymarket, the platforms that let users trade on the outcome of events, including sports.

The foundation says the omission is practical. Access to betting data from those platforms is severely limited, its spokeswoman said, which makes rigorous independent evaluation difficult. Prediction markets are also regulated federally by the Commodity Futures Trading Commission, so they offer none of the state-by-state variation the studies depend on.

That variation is the backbone of the method. Most of the funded work compares states according to when they legalised online sports betting, an approach that lets researchers isolate the effect of the decision itself.

Arnold Ventures has been careful about how it frames the exercise. Asked which argument it considers most persuasive with lawmakers, whether financial harm, mental health, the integrity of athletes or disappointing tax receipts, the spokeswoman said the foundation does not approach the question through a single lens. It is not funding the research, she added, to support a predetermined legislative outcome or any position on legalisation.

The grants are a small item against the Arnolds' wider giving. The couple had donated more than $2.3 billion as of February, most of it to criminal justice and education causes, and Forbes puts John Arnold's fortune at around $2.9 billion.

They signed the Giving Pledge in 2012. A 2025 report by the Institute for Policy Studies identified them as the only signatories technically in compliance with the promise to give away at least half of one's wealth, a record that Melinda French Gates has invoked in criticising other billionaires for not giving enough. The Arnolds have said they will leave no legacy foundation behind them.

The money came from natural gas. Arnold finished a degree in mathematics and economics at Vanderbilt in three years, joined Enron as an oil analyst and was running the company's Texas natural gas desk in his twenties. He is reported to have earned Enron $750 million in 2001, the year it collapsed in what was then the largest corporate bankruptcy in American history. He was never accused of wrongdoing.

He founded Centaurus Advisors in Houston in 2002 with the $8 million bonus Enron paid him days before the filing. The fund made its name in 2006 by taking the other side of a wager by Amaranth Advisors, which lost about $5 billion betting that gas prices would rise. Arnold became the youngest billionaire in the United States in 2007 and closed the fund in 2012, aged 38.

Philanthropy has been his occupation since. Arnold Ventures, established in 2008 and later restructured, employs about 150 people across New York, Washington and Houston. Arnold joined Meta's board in 2024, sits on the board of Breakthrough Energy and chaired Houston's bid to stage matches at this year's World Cup.

The pattern he describes reaches well beyond the United States. Mobile-first betting has spread quickly across Africa, where operators including Kenya's SportPesa built large businesses on cheap smartphones and mobile money, and where governments in Nairobi, Abuja and Accra have spent years arguing over how to tax and police the industry.

Research of this kind takes years, and legislatures are not waiting. Arnold's wager is that the evidence will eventually arrive in a form lawmakers can use, whatever they decide to do with it.