Sam Altman is selling his most expensive property for $49 million. It has 10 bathrooms

Sam Altman had once described the property as a 'lemon'. (File photo)

OpenAI cofounder and CEO Sam Altman is selling his oceanfront mansion on Hawaii’s Big Island for $49 million, Forbes reported. Public records show the 10-bedroom estate was listed approximately two weeks ago, with the property registered under Big Surf LLC—a company previously tied to Altman’s San Francisco residence and currently linked to his Napa Valley ranch and venture capital operations.

The listing describes the property as offering “exceptional privacy” and “advanced security systems that guarantee peace and discretion.” Built in 2011, the estate includes a five-bedroom guesthouse, 10 bathrooms, a private marina, and a movie theater. Sotheby’s agent Brian Axelrod, who is handling the sale, called it “the most amazing property I’ve ever seen during my career.” Axelrod declined to comment on buyer interest or the current stage of the sale process.

While OpenAI has not confirmed Altman’s ownership, Big Surf LLC was previously registered to Altman’s San Francisco home—the subject of a lawsuit in which Altman described the property as a “lemon.” The LLC is now registered to a Greenville, South Carolina address associated with Altman’s Napa ranch and Hydrazine venture capital funds. Big Surf’s listed manager is Altman’s cousin Jennifer Serralta, COO of a family office and a known associate in several Altman-linked LLCs. Serralta declined to comment.

Altman purchased the Hawaii estate for $43 million in 2021, around the same time he acquired his San Francisco home for $27 million and a 950-acre Napa ranch for $16 million. According to Forbes, Altman’s estimated net worth is $2 billion, largely derived from early-stage tech investments rather than equity in OpenAI, which he has described as “immaterial.”

The timing of the sale coincides with OpenAI’s reported secondary share sale worth $10.3 billion, which could value the company at up to $500 billion. If Altman’s claims about his stake hold, he will not benefit from the transaction.