Sergey Brin has ties to a $51 million mansion that just sold in Miami

• A home on Miami's Allison Island sold for $51 million on Tuesday.
• The purchaser has ties to Google cofounder Sergey Brin.
• Tech billionaires have been flocking to Miami as California weighs a wealth tax.

The latest mega-sale in Miami — a $51 million waterfront mansion — had been completed, and the deal has ties to Google cofounder Sergey Brin.

If Brin is confirmed as the new owner, that would mean four of the five wealthiest people in the world now own homes within about 20 square miles. Three of those purchases — those of Brin, his Google cofounder Larry Page, and Meta CEO Mark Zuckerberg — were completed over the past few months. Elon Musk, the wealthiest person in the world, is the only holdout.

The rush of tech titans buying homes in Miami comes amid criticism of a proposed wealth tax in California that, if passed, would subject residents with a net worth of more than $1 billion to a one-time 5% tax on their wealth.

On Tuesday, a deed was recorded for a home on Allison Island, an exclusive enclave in Miami's Biscayne Bay. The $51 million sale was from MB 1 LLC, owned by Michael Burke, the chairman and CEO of LVMH, to Lagoon LLC, a corporation registered at a Reno, Nevada, address with attorney Michaelle Rafferty listed as an officer.

Brin's name is nowhere near the transaction, but both Rafferty and the Reno address, which matches that of Rafferty's law firm, appear on previous real estate purchases linked to Brin.

Alpine Bay LLC, which owns a Lake Tahoe property reportedly purchased by Brin, is registered to the same Reno address. Christine Wade, a lawyer Brin has used for several other property transactions, is listed as an officer of Alpine Bay LLC. A Malibu property also linked to Brin is owned by Dume Cove LLC, which was converted out of California in December by Christine Wade. A few days later, a Dume Cove LLC was incorporated in Nevada with Rafferty named as a manager.

Rafferty and representatives for Brin's family office did not respond to requests for comment from Business Insider.

Last month, the New York Post reported that Brin had made an offer on an Allison Island home that had not yet gone through.

The transaction was off-market, which means the waterfront property was not listed for sale, so photos and other details are sparse. The house was built in 2019 and has nearly 10,000 square feet of living space, according to property assessments. It features a cabana, a marble patio, a luxury pool, and a hot tub, all installed in 2019.

The price tag marks a record for Allison Island. Luxury real estate in Miami Beach, including hot spots like Indian Creek and Coconut Grove, has reached new heights of late, in part due to an influx of billionaires from California, real estate agents recently told Business Insider.

Beginning in December, Page spent over $180 million on three properties in Coconut Grove and moved several companies out of California.

"What just happened was that there was a ringleader, Larry Page, who closed on his property the last days of December, and that sounded the alarm for the others," Douglas Elliman agent Dina Goldentayer told Business Insider in February.

On Monday, Bloomberg reported that Zuckerberg paid a record-breaking $170 million for a single property on Indian Creek Island, joining a small community that includes Amazon founder Jeff Bezos and Ivanka Trump.

Danny Hertzberg of the Jills Zeder Group was the listing agent for one of the homes purchased by Page, as well as the $170 million property on Indian Creek Island. In January, he told Business Insider that the wave of Californians toward the end of 2025 and into 2026 was unanticipated, but as more people came started to make sense.

"People want to be around their colleagues," he said. "They want to be around people in technology and finance. So it's made a big impact on the market."

The prices have skyrocketed, in what Goldentayer described as a gold rush, as sellers sitting on exclusive acreage pretty much get to name their price.

"If they build it, someone will come for it," she said. "I truly believe that. That's what keeps me motivated every day."