WhatsApp Co-Founder Jan Koum Assembles an $80 Million Atherton Compound

The leafy California town of Atherton has long garnered fame for its residents, many of whom are among the nation’s wealthiest. In the decades following its 1860s beginnings, when city founder Faxon Atherton and other Gold Rush-rich capitalists chose to build their country estates in the area, Atherton became known as a bastion of quiet old money. But since the turn of the century, the Silicon Valley tech boom has brought in a breed of new hyper-money from Palo Alto and China to town, shocking longtime residents with the ensuing construction boom and still-skyrocketing real estate prices they have engendered. This swarm of youthful billionaires — many of whom employ their own bodyguards and security teams — favor elaborate compounds and high-tech amenities. And there’s perhaps no more extreme example than the home of Jan Koum, the Ukraine-born immigrant who became an overnight multibillionaire in 2014.

When the five-year-old messaging service WhatsApp was acquired by Facebook in an unprecedented $19 billion deal, Koum and his co-founder Brian Acton instantly joined the Forbes 400. While both remained at Facebook for a time, they eventually departed — Acton in 2017, Koum the following year — amid reports both men had clashed with Mark Zuckerberg and Sheryl Sandberg over data privacy concerns.

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WhatsApp Co-Founder Jan Koum Assembles an $80 Million Atherton Compound

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Koum’s goodbye post stated he was leaving Facebook to collect rare air-cooled Porsches and play ultimate Frisbee. And any bonafide car collector — or hardcore frisbee collector, for that matter — needs a fancy garage, so Koum has set about fashioning himself a world-class example.

Over the last four years, Koum has paid $57 million in five separate transactions to assemble a monumentally scaled Atherton compound. All five of the houses he acquired have either been razed entirely and replaced with all-new structures, or radically reimagined. Permits show he has spent an additional $20 million-plus for the site’s multiple new structures, including at least two separate mansions and a state-of-the-art, two-level detached garage that appears to span well over 10,000 square feet — in fact, the garage alone dwarfs some of the neighboring Atherton homes.

Although no high-quality photos of the Koum compound are publicly available, Ferrari apparently snagged a brief tour of the garage last year. And it’s all but certain that the near-$80 million listed in records is merely a very conservative estimate of the cost to complete an estate of these proportions — when landscaping and customization spends are factored in, the total pricetag will likely skew far higher. Upon completion, Koum’s compound will probably be the most expensive Atherton property ever constructed.

For reference, Atherton’s three priciest real estate transactions appear to have occurred between 2011 and 2015. Back in May 2015, a giant spec-built mansion up the road from Koum’s compound transferred for $35.3 million in cash to philanthropist Yasmin Lukatz, a mere three weeks after being listed for sale. (Lukatz is the stepdaughter of multibillionaire casino kingpin Sheldon Adelson.)

In May 2014, a mysterious buyer identified only as a “billionaire Chinese tech CEO” paid exactly $40 million for a 12,636 sq. ft. manor house on one of the city’s most prestigious streets. But the biggest-ever sale went down back in September 2011, when someone paid $53 million for the so-called Pine Brook Estate, a 12-acre spread in central Atherton. Though the buyer — who later spent an additional $23 million to acquire three neighboring properties — has never been publicly named, a deep dive into records reveals the property has multiple indirect links to Google co-founder Sergey Brin.

And as for Koum, he also still owns his “starter” Atherton house — a 3,715-square-foot traditional that’s located about a mile from his lavish new compound. He picked up the comparatively puny property back in early 2015, for $8.8 million.

Launch Gallery: Jan Koum's $80 Million Atherton Estate

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