OpenAI CEO Sam Altman went on an 18-month, $85 million real-estate shopping spree — including a previously unknown Hawaii estate

• OpenAI CEO Sam Altman owns multi-million dollar properties in San Francisco, Napa, and Hawaii.
• Altman, who was fired and then reinstated as CEO of OpenAI this month, has tried to keep a relatively low profile. 
• When BI set out to catalog his assets, we found a giant estate that's previously unknown.

Years before the recent drama at OpenAI turned CEO Sam Altman into a household name, the former Y Combinator president went on an extraordinary 18-month, $85 million real-estate shopping spree, according to records reviewed by Business Insider — including a previously unreported $43 million Hawaii estate on land that locals describe as historically significant.

The purchases, which also include multi-million-dollar residences in San Francisco and Napa, California, took place between early 2020 and mid-2021, when Altman was ginning up support for his eyeball-scanning crypto startup Worldcoin and releasing OpenAI products in private beta, Business Insider's review of business and real estate filings shows.

A spokesperson for Altman declined to comment.

Altman's precise net worth isn't known. As the CEO of OpenAI, his salary is just $58,333, according to IRS filings, and his equity stake in the company is so small as to be "immaterial," he's said. He's made more than 400 investments in nine years, Insider previously reported, in companies working in fields as diverse as commercial flight to brain implants.

Earlier this year, Altman seemed to take a subtle dig at his fellow tech executives for amassing too much wealth.

"This concept of having enough money is not something that is easy to get across to other people," Altman said at the Bloomberg Tech Summit in San Francisco.

But as Altman's wealth has grown, he's become increasingly removed from the daily life of the non-ultra-ultra-rich. His mother told the Wall Street Journal in March that Altman hadn't been to a grocery store in four or five years. In 2021, he hired his cousin to manage his family office.

Here's where Sam Altman spends his time.

A $43 million estate in Hawaii

In July 2021, Altman bought a twelve-bedroom estate in Kailua-Kona, on the big island of Hawaii, for $43 million. Judging by listing photos, the property has a private inlet and several houses. The estate is adjacent to a national landmark, a reconstruction of the royal temple of King Kamehameha, the first ruler of a unified Hawaiian islands.

"This land here is very sacred," the security manager of the property said in a recent video posted on YouTube about the estate urging visitors to be respectful. The property, he said, "is presently on the platform that the original house of King Kamehameha I resided," adding that the land is "one of the most historical places here in Hawaii."

A second video highlighted the estate's adventurous amenities, including cliff jumping, motorboating, wakesurfing, jet skiing, and scuba diving. A person who worked on the second video said the intent was to produce something that friends and family could watch to remember their trips to the residence. (Both videos were removed from YouTube after BI requested comment for this article.)

Altman's purchase of the Hawaii property has not been previously reported. Business Insider linked the property to Altman by examining business and real estate filings that show the land is owned by an LLC managed by Jennifer Serralta, whose name appears as a manager on paperwork for other businesses known to be owned by Altman. Serralta, who previously worked in the automotive industry, describes herself on LinkedIn as the COO of a family office — presumably Altman's — and is his cousin, according to an obituary for their grandmother. Reached by phone, Serralta declined to comment.

Family offices are entities established to manage the finances and investments of wealthy individuals, wrangling everything from real estate to yachts and philanthropy. Altman's, like those of many Silicon Valley tech CEOs, is intensely private. Altman has launched several investment vehicles over the years, including one with his brothers Jack and Max named Apollo Projects, and another entity titled Altman Family LLC.

In a March post on her personal blog, Serralta wrote that she stayed at a Kailua-Kona property owned by "a friend" while vacationing in Hawaii. Last year, Altman tweeted a photo of himself wakesurfing in Hawaii; the view of the Big Island in the background of the photo matches precisely the view from the Kailua-Kona compound. And in 2021, Altman registered a business, the Sam Altman Qualified Opportunity Fund, at an address adjacent to the property. (It's possible that Altman wanted to register the business to his address but made a mistake; the address he used differs from his own by just one digit and has been owned by the same person since 2007.)

Altman joins a roster of Silicon Valley titans with Hawaii estates, including Mark Zuckerberg, whose property purchases on the island of Kauai have sparked controversy, and Larry Ellison, who owns most of the island of Lanai. Marc Benioff, Jeff Bezos, and Peter Thiel have also scooped up sizable properties on the islands.

Altman has one family connection to Hawaii: His youngest sibling, sister Annie Altman, has lived on the islands on and off since 2017. Annie, an artist and entertainer who has supported herself through in-person and virtual sex work, lives a much different life than her brother. Annie is teetering on financial insolvency, she told BI, after a lengthy stretch of illnesses. She has not spoken to her brother since 2021, when Annie refused Sam's offer to buy her a home after learning that a lawyer would control the property, she said.

Annie had been unaware that her oldest brother owned property in Hawaii until Business Insider asked her about it, she said.

A $27 million San Francisco home

Altman's weekday residence is a home on San Francisco's Russian Hill that was once described — inaccurately — as the most expensive home in San Francisco. He purchased it through an LLC in March 2020 for $27 million, according to property and business records.

The compound, with sweeping views over San Francisco, includes a main residence, a wellness center, a cantilevered infinity pool, and an underground garage with a car turntable, Business Insider reported earlier this year.

The property is the home base for a number of Altman's investment vehicles, according to business and SEC filings, including venture firm Apollo Projects, 9Point Ventures, and Uncommon Ventures. In recent weeks, the property functioned as a war room for Altman and his closest allies as he planned his return to OpenAI.

A $15.7 million ranch in Napa

Altman took a New York Times reporter to his weekend home, a working ranch in Napa, earlier this year. The reporter, Cade Metz, described the estate as "both folksy and contemporary. The Cor-Ten steel that covers the outside walls is rusted to perfection."

Altman purchased the 950-acre property in late 2020 for $15.7 million through an LLC, according to real estate records reviewed by Insider. The estate comprises five homes and vineyards in a picturesque northern California landscape.

Several Altman companies are or have been registered to the address, including the opaquely-named Project 2024 LLC, as well as another Altman venture firm, Hydrazine Capital Management.

At the time of purchase, one of the property's former owners described the buyer, who he did not name, as having "complete passion for the land."

"It's hard to explain how marvelous it is to live where there are still river otters on your property and oaks that are centuries old. He gets it. He's enthusiastic about it," the former owner, Hollywood lighting designer Bob Dickinson told the San Francisco Chronicle. "He has a very close family and I think his motivation is to make it the same kind of community experience with his family and friends."

Altman flies groups of friends and colleagues up to the property frequently.

A "big patch of land" in Big Sur, cars, and planes

In 2016, Altman told the New Yorker that he owns a getaway in Big Sur that he can "fly to" if a super-powerful AI attack leads to "nations fighting with nukes over scarce resources." (He also said he had stockpiled "guns, gold, potassium iodide, antibiotics, batteries, water, gas masks from the Israeli Defense Force" to prepare for that event.)

Business Insider wasn't able to find which "big patch of land" Altman owns in the expensive coastal California enclave, but it seems likely he'll be able to fly himself there in the event of an apocalypse: A 2010 document shows Altman is licensed to fly single-engine planes, and he's posted about small plane trivia on X. In the same New Yorker interview, Altman also copped to owning five cars, including two McLarens and an "old Tesla." Altman posted on X in 2014 about owning a Tesla Roadster, of which only 2,450 were made. The cars are now collectors' items selling for more than $100,000. He's also posted about owning a 2013 Tesla Model S.

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