The U.S. men’s national team’s World Cup run ended Monday night in Seattle, where Belgium beat the Americans 4-1 in the round of 16, eliminating the last of the tournament’s three co-hosts. The loss still made history: It the most-watched soccer telecast in U.S. history, with the audience peaking at more than 36.8 million viewers between 9:15 and 9:30 p.m. ET., according to Fox, which said 30 million people watched the match. That topped the previous American soccer ratings record, set just a week earlier by the U.S.-Bosnia and Herzegovina match, which drew 26.4 million viewers.

That kind of fan support is evidence for Citadel founder and CEO Ken Griffin, a soccer obsessive who personally had a hand in bringing star coach Mauricio Pochettino to the men’s national team, someone whom many consider is the reason why this is the first time in 24 years (and second in the team’s history) the Americans have won a World Cup knockout match. Getting there took a coach U.S. Soccer couldn’t otherwise afford, and that only happened thanks to help from the billionaire.

“I’m pleased to see the progress the U.S. Men’s National Team has made under Mauricio’s leadership and the excitement this World Cup has generated across America,” Griffin told Fortune following the results of Monday night’s loss. “I look forward to building on that momentum in the coming years.”

Soccer’s biggest philanthropist

Griffin started playing soccer at age 6, competed on a state runner-up high school team in Florida, and continued playing and coaching—including his own children’s teams—into adulthood. That personal history has translated into a long philanthropic record around the sport. He’s donated an estimated $2.5 billion to charitable causes overall, including a recent $26 million gift for a Theodore Roosevelt presidential library timed to the country’s 250th anniversary. For soccer specifically, Griffin gave $3 million in 2017 to fund 50 mini-pitches across Chicago, where Citadel was then headquartered, and followed with a $5 million gift in 2023 for another 50 mini-pitches in Miami-Dade County after relocating the firm’s headquarters there.

Together, the 100 mini-pitches have expanded access to safe places to play for more than 100,000 kids and families in underserved communities, earning Griffin the U.S. Soccer Foundation’s #10 Award this year which recognized him as its most impactful philanthropist.

That track record is what put Griffin in the room when U.S. Soccer needed a rescue plan. A Citadel spokesperson confirmed to Fortune the push to land a marquee coach began with an offhand text to friends from Scott Goodwin, co-founder of hedge fund Diameter Capital Partners. Goodwin spoke with U.S. Soccer chief executive JT Batson, who told him the federation’s leading candidates were unaffordable. So Goodwin turned to Griffin.

Unlike most national federations, U.S. Soccer receives no direct government funding, relying instead on its own revenue, sponsorship, and donations. Of the federation’s $264 million in revenue last year, $50 million came from donations, more than half of it restricted in how it could be spent. Griffin’s contribution—confirmed by a Citadel spokesman to Fortune as the largest financial contribution among a group of benefactors who helped hire Pochettino—closed the gap on a deal that would otherwise have been out of reach. Griffin said at the time the donation would help the team succeed, which “expands the reach of this great sport.”

Pochettino, who previously managed Tottenham Hotspur, Paris Saint-Germain, and Chelsea, was brought in on a two-year deal to rebuild a U.S. squad that had just been eliminated from the 2024 Copa America. He’s now the highest-paid coach in U.S. Soccer history, earning a base salary of roughly $6 million a year, with tax filings showing he collected more than $5 million in his first seven months on the job, including a signing bonus of about $2.5 million.

On the field, the investment produced a strong run under the tournament’s expanded 48-team, round-of-32 format: the U.S. opened with a 4-1 win over Paraguay, then beat Australia 2-0 to top its group despite a 3-2 loss to Turkey, before a 2-0 win over Bosnia and Herzegovina in the round of 32—a match that included a controversial red card against striker Folarin Balogun that FIFA later suspended.

Griffin’s giving around the 2026 tournament has extended to who gets to experience it, echoing efforts elsewhere to widen access to a tournament otherwise defined by record-high prices. Griffin Catalyst has funded nonprofit-hosted watch parties at its Miami mini-pitches, complete with match broadcasts, soccer activities, music, and food, and the organization is an Official Miami World Cup 2026 Host City Supporter and sponsor of the FIFA Fan Festival Miami. Griffin, along with Miami Dolphins owner Stephen Ross, also donated more than 1,200 World Cup tickets to youth served by Boys & Girls Clubs across Miami-Dade, Broward, and Palm Beach counties.