Greth owns about one-third of Diamondback Energy, a Midland, Texas-based oil and natural gas company. She received the shares from her family's sale of closely held driller Endeavor Energy Resources to Diamondback for $26 billion in cash and shares in 2024. Her father Autry founded Endeavor in 1979.
The majority of Greth's fortune is derived from a 30% stake in publicly traded oil company Diamondback Energy. She holds the stake through SGF FANG Holdings, LP, according to a March 2026 13D filing. She received those shares as part of her father's sale of closely held driller Endeavor Energy to Diamondback in 2024 for $26 billion in cash and shares. Her father Autry Stephens agreed to sell the company in February 2024 and died in August 2024.
The family received more than $10.5 billion in cash, before tax, in connection with the sale. The analysis assumes that the family paid long-term federal capital gains tax on that windfall. The billionaire's cash portfolio is adjusted for tax, dividends, market performance, and philanthropic donations.
Bloomberg's valuation was updated to include a block sale of about $2.6 billion in Diamondack Energy shares and a $2 billion donation to the Stephens Greth Foundation on March 31, 2026, causing a one-day net worth decrease of about $2.4 billion.
Any shares or proceeds from share sales, including those held by her mother Linda Stephens, and brother, Joseph Martin Stephens, are attributed to her.
A spokesman for Diamondback didn't respond to requests for comment.
Lyndal Stephens Greth was born in the mid-1970s to Autry and Linda Stephens. Her father was an oil engineer who grew up on a watermelon and peanut farm in a small town in Texas. Shortly after Lyndal was born, Autry left his job as an appraisal engineer at a Midland bank and struck out on his own, taking inspiration from the entrepreneurial clients he met.
Over the following decades, he transitioned from an engineer-for-hire with little to his name to an oil tycoon, buying up drilling rights and branching into various ancillary businesses such as trucking, well services and roustabout construction. He poured profits from drilling wells back into the business and used them to buy more land. His company, Endeavor Energy, eventually became the biggest closely-held oil producer in the country.
Greth graduated with a degree in English from Southern Methodist University in 1997 and went on to earn a law degree from Baylor University. She worked as an attorney for various firms before joining Endeavor's board in 2013 as vice chairman. She became chairman of the board upon her father's death at age 86 in 2024. She lives with her husband Richard Greth, a real estate investor, in Dallas.