Jessica Pegula has an opportunity to make history at this year's U.S. Open. Ranked No. 3 in the world, Pegula is at the peak of her career and facing what may be her best chance yet to capture a first Grand Slam title. A deep run in the tournament could also make her the first American woman to claim the No. 1 spot in the WTA rankings since Serena Williams did so more than a decade ago.

At 32, Pegula has already assembled a remarkable career both on and off the court, earning more than $26 million in tournament prize money and signing endorsement deals with companies including IBM, Hyatt, and The Farmer's Dog. She has also reached the top of the sport in doubles, having held the WTA No. 1 doubles ranking in 2023. Yet one aspect of her story has followed her throughout: her family's extraordinary wealth.

Her father, Terry Pegula, amassed his fortune in the oil and gas industry before redirecting much of his attention—and billions of dollars—toward professional sports. He sold the bulk of his company, East Resources, to Royal Dutch Shell for $4.7 billion in 2010. The next year, he bought Buffalo, New York's NHL franchise, the Buffalo Sabres, for $189 million, and in 2014 he outbid groups that included Jon Bon Jovi and Donald Trump to acquire the NFL's Buffalo Bills for $1.4 billion. Today, Terry and his wife Kim Pegula have a combined net worth of approximately $9.3 billion.

For Jessica, however, her father's fortune is something she has tried not to let define her as a professional athlete.

"I've always tried to carry myself as just a normal person because that's to me how I am," Jessica told The Times earlier this year. "I'm definitely aware that I was very privileged and had a lot of good opportunities, and I didn't want to waste those."

Terry Pegula turned a $7,500 loan into an oil empire—and his daughter shares his work ethic

Terry Pegula grew up in rural northeastern Pennsylvania, where his father worked as a truck driver and coal miner. He initially studied mathematics at Penn State University before transferring into the school's Petroleum and Natural Gas Engineering program, graduating in 1973.

After college, he moved to Texas to work for Getty Oil Company, later returning to the Rust Belt. In 1983, he borrowed $7,500 from family and friends to found East Resources, an independent oil and gas exploration and production company operating in the Appalachian Basin.

Over nearly three decades, Terry Pegula grew the company into one of the largest privately held oil and gas businesses in the United States, ultimately selling the bulk of East Resources to Royal Dutch Shell for $4.7 billion in 2010. He sold another $1.75 billion in assets in 2014.

For Jessica, that story of starting with relatively little and building something through persistence sits at the heart of her family's ethos. Born in 1994, she began playing tennis at age seven, but she has said her family did not become wealthy until she was a teenager.

"My dad is super blue-collar," Jessica told The Times. "He grew up with nothing and built his way up, and that mindset was instilled in my family from a young age."

"Some people get this image that it's really easy for me because my dad is very wealthy, but that didn't happen till I was 17 or 18," she added.

By that point, Jessica had already shown promise as a young tennis player. At 17, she received a wildcard into the main draw of the U.S. Open doubles tournament in 2011, and four years later she made her singles debut.

Her rise to the top of the sport, however, has been gradual. Now 32, she has been described as a "late bloomer" by tennis standards. Her career-best Grand Slam result came at the 2024 U.S. Open, where she reached the final before falling to Aryna Sabalenka. The two players ranked above her in the WTA standings—No. 1 Aryna Sabalenka and No. 2 Elena Rybakina—are 28 and 27, respectively, and have each already won multiple Grand Slam titles.

Jessica, by contrast, is still pursuing her first major trophy—and has said her goal has always been to one day reach the No. 1 ranking. Neither her age nor her family's wealth, she said, changes what it takes to get there.

"Everyone who knows sports, or is an athlete, or is highly competitive, or has made it very far, I think, knows that you're not really going to get there unless you work hard, are talented, and are really driven to get there," Jessica told Forbes in 2023. "It's really difficult."

That philosophy mirrors the advice Terry has given his children throughout their lives: "Work hard, love what you're doing, and treat people right."

On Friday, Sept. 4, Jessica defeated No. 31 Leylah Fernandez to advance to the fourth round of the 2026 U.S. Open, where she will face No. 16 Sorana Cirstea of Romania. Fortune reached out to the Pegulas for comment but received no response.

Many of tennis's biggest stars came from modest beginnings—and built fortunes of their own

Jessica Pegula is not the only rising tennis star to come from a high-net-worth family.

Emma Navarro, the No. 26 seed at the U.S. Open, is the daughter of Ben Navarro, whose net worth is estimated at $3.2 billion following a career in finance. Like the Pegulas, Emma has emphasized the role her family's work ethic played in her own success.

"My family instilled in me the value of hard work, resiliency, and perseverance," Emma said earlier this year. "My dad always taught us to never give up no matter the circumstances and to always give one hundred percent effort in everything you do."

Still, there is no single formula for becoming a successful tennis player. Although the sport can be expensive to enter, with high costs for coaching, equipment, and club memberships, some of its top stars come from families without enormous fortunes—and many have gone on to build multimillion-dollar fortunes of their own.

Serena and Venus Williams, for instance, grew up in a middle-class family in Compton, California, before becoming two of the most successful and recognizable players in tennis history. Serena's net worth is estimated at $400 million, while Venus has accumulated more than $50 million through prize money, endorsements, and investments.

The sisters have often credited their upbringing with shaping their careers.

"I think the main value that [my parents] instilled in me is just humility, and I think that goes way better than any championship or anything, because it keeps you grounded as an individual," Williams told CNBC. "It keeps you respectful, and it keeps you just like everybody else, because at the end of the day, we're all the same."

Novak Djokovic, who has won more Grand Slam singles titles than any other male player, has likewise emphasized the sacrifices his parents made to support his tennis career. As a child, the Serbian star recalled his father telling their family of five that they had just $10 left to their name—a lesson in persistence that stayed with him.

"Go forward no matter what, fall hard on your nose, and then stand up and keep going forward and fall again and then bounce back again," Djokovic said. "And then, you will win."

This story was originally featured on Fortune.com.