Atherton knocked off its pricey perch by Florida’s bougie billionaire island

Fisher Island replaces the tony Silicon Valley town as the nation’s most expensive place to buy a home.

https://sfstandard.com/2025/10/19/atherton-miami-fisher-mansions-expensive-zip/

Atherton has had eight $20 million-plus homes sold this year. | Source: Matt Anello/Blu Skye Media

A community in Florida — of all places — has stolen Atherton’s long-held crown as the country’s most expensive ZIP code, according to new data from PropertyShark. 

It’s not that the tony Peninsula enclave 30 miles south of San Francisco has gotten any cheaper, according to PropertyShark’s Eliza Theiss. It’s just that Miami’s Fisher Island 33109 ZIP saw an even bigger 65% price jump — from a median of $5.75 million last year to $9.5 million in the first nine months of 2025. Atherton’s median hit a new high of $8.33 million, but that still paled in comparison with its rival in South Florida.

Atherton has had eight $20 million-plus homes sold this year. | Source: Matt Anello/Blu Skye Media

Atherton, which held firmly onto PropertyShark’s top spot for the last eight years, had three times the sales volume of the exclusive Florida barrier island, which has fewer than 1,000 residents. Fisher Island, which is stacked with luxury condos, had only three sales over $20 million, compared with eight in Atherton. 

Atherton has held the top spot for so long that it was probably only a matter of time before some other place overtook it, said Compass agent Tom LeMieux, who specializes in luxury Peninsula sales. But the market — and the multimillionaires who make it up — are doing just fine, thank you. 

“Cheers to Miami or wherever it is in Florida that outpaced us, at least for this period of time,” he added. “We’ll try to get back into that No. 1 position soon.”