Jane Street’s Mysterious Trading Billionaire Is Smashing Records

Oct. 2, 2025, 10:00 AM UTC

Rob Granieri took to the dance floor with long hair flowing from his fedora, shiny jacket glinting and a boutonnière bursting with color.

The wealthy recluse showed off his moves after platters of paddlefish caviar and bacon-wrapped shrimp swirled through the room to celebrate his Scarlet Pearl, the casino hulking over Mississippi’s brackish Biloxi Bay. The disco-bright veneer gave the revelers no hint of the 53-year-old billionaire’s hidden reality.

Rob Granieri
Photo Illustration by Jimmy Turrell; Photos: Facebook

Far away from slot machines and roulette, this is the man piling up billions of dollars as the last founder standing at Jane Street, the black-box money machine minting Wall Street ...

Learn more about Bloomberg Law or Log In to keep reading:

Learn About Bloomberg Law

AI-powered legal analytics, workflow tools and premium legal & business news.

Already a subscriber?

Log in to keep reading or access research tools.