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, 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.”
There’s not a lot of overlap between buyers in the two markets. South Florida largely attracts wealthy New Yorkers drawn to the tax breaks and the sunshine of the Sunshine State, while Atherton has buyers searching for grand homes and good schools in the heart of Silicon Valley.
Atherton’s ties to tech and the Nasdaq meant that the usual frenzied spring was muted, due in part to President Donald Trump’s tariffs roiling the markets. But those hesitations seem to be in the rearview mirror this fall, noted LeMieux, who recently went into contract on a 10,000-square-foot, $25-million Atherton listing he’s been representing since April. “It was a short pause, and we quickly recovered, and now the market has marched on.”
The PropertyShark list revealed the country’s top 100 ZIP codes for sales over $2 million, and the Bay Area featured prominently, taking about a third of the slots. Marin County’s Stinson Beach ZIP jumped up by over $1 million, just breaking the $5 million median barrier. Outside of Fisher Island, Water Mill and Sagaponack in the Hamptons were the only non-California locations to crack the top ten.
Santa Clara County accounted for 15 of the 100 most expensive ZIP codes, making it the second most expensive county in the country after Los Angeles County. Bel Air was the priciest market in the SoCal locale, with a median of $3.55 million.
Only one ZIP code in San Francisco made the grade: The Marina and Cow Hollow’s 94123 came in 74th on the list with a median of $2.35 million, tying Mountain View. Pre-pandemic, the city had 13 top ZIP codes, according to PropertyShark, indicating a luxury market failing to keep pace with the rest of the super-elite Joneses.