The reclusive billionaire co-founder of Wall Street hedge fund Jane Street is an unkempt hippie who has spent his wealth on Burning Man boondoggles, casinos and funding a coup in Africa, according to a report.
Rob Granieri, who hired Sam Bankman-Fried out of college before he became known as the infamous cryptocurrency trader who went to prison for fraud, may be the most powerful Wall Street billionaire you’ve never heard of.
The last remaining co-founder of Jane Street, the secretive trading giant that pulled in $17 billion during the first half of 2025, has no official title and no headshot in the company directory, according to Bloomberg News.
That invisibility has grown harder to maintain as Jane Street’s profits exploded. The firm now handles more than 90,000 products across 240 exchanges and accounted for nearly a quarter of all US-listed ETF trading volume last year.
With $53 billion of its own capital, Jane Street raked in $17 billion in the first half of 2025 alone — earning in two weeks what once took a year.
Meanwhile, Granieri, 53, often goes unrecognized, even inside his own firm. He has built a fortune by keeping himself and his company out of view, thriving on a mix of secrecy, eccentricity and contradiction, Bloomberg News reported.
Known for working odd hours, shunning long vacations and showing up in rumpled clothes, he has spent decades enforcing Jane Street’s invisibility — once fuming when a young trader was quoted as saying that his job was secure during the financial crisis.
Granieri himself has no official title at the firm he co-founded in 1999 after splitting from trading powerhouse Susquehanna. In the company directory, his profile stands out for lacking even a headshot.
Earlier this year, however, Granieri made headlines when he was allegedly tricked into funding a plot to purchase assault rifles, Stinger missiles and grenades that were used to stage a failed coup in South Sudan.
Granieri was never charged with a crime.
He lives like a recluse in Manhattan, dressing in schlubby clothes at the office while cutting loose at Burning Man or his Mississippi casino, according to the report.
With his fedora and penchant for ponytails, he looks more like a bohemian artist than the head of one of Wall Street’s most profitable trading shop.
At Jane Street, Granieri inculcated a culture that mirrors his quirks. Employees wager on anything — coin tosses, weight-gain contests, even “Money in the Hat,” where staff stuff bills and names into a cap before a winner is drawn.
Traders even made markets on who would go home with a female colleague, prompting Granieri to send a stern memo warning: “Don’t make the situation worse by talking about it, making jokes, placing bets.”
Jane Street’s Manhattan offices boast an in-house chef, rooms designated for poker games and video games, according to Bloomberg News.
The Post has sought comment from Jane Street.
Unlike other billionaires who scoop up trophy homes, Granieri prefers renting apartments — a habit that once landed him in court over a $10,372 unpaid bill, Bloomberg News reported.
His only real indulgence is food: colleagues recall him joking that there was no need to cook when he could eat at Manhattan’s Le Bernardin every night, according to the report.
Away from Wall Street, he pours money into the Scarlet Pearl, a Mississippi casino where he stunned managers in 2019 by approving Jim “Mattress Mack” McIngvale’s $3.5 million bet on the World Series.
McIngvale, owner of Houston’s Gallery Furniture, placed the bet on the Houston Astros to win the 2019 World Series. The Astros went on to lose the World Series in seven games to the champion Washington Nationals.
At Burning Man, he once helped build a geodesic dome packed with yoga balls. He called the exhibit “Balls Deep.”
LuAnn Pappas, who runs the Scarlet Pearl, admitted she was stunned to learn her boss would spend days in the Nevada desert “like the hippie movement,” unshowered and grinning as he mingled with artists.
