Jessica Pegula has a chance to make history at this year’s U.S. Open tennis tournament. Currently No. 3 in the world, Pegula is riding a career high and facing down her greatest opportunity yet to win her first major. A deep run could also make her the first American woman to reach the top spot in the WTA rankings since Serena Williams over a decade ago.

Pegula, 32, has already built an impressive career on and off the court, earning over $26 million in tournament prize money while securing brand deals with companies including IBM, Hyatt, and The Farmer’s Dog. But there’s another part of her story that has long followed her around: her family’s extraordinary wealth.

Her father, Terry Pegula, built a fortune in the oil and gas industry before turning 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 following year, he purchased Buffalo, New York’s NHL team, the Buffalo Sabres, for $189 million, and in 2014, he outbid groups including Jon Bon Jovi and Donald Trump to purchase the NFL’s Buffalo Bills for $1.4 billion. Today, he and his wife Kim Pegula have a combined net worth of about $9.3 billion.