Ken Griffin Buyer in $38M Deal For 740 Park Ave Duplex

An apartment in an Upper East Side co-op — dubbed New York City’s “richest building” — traded for a rich premium, and to a buyer who’s no stranger to trophy deals.

A duplex at 740 Park Avenue sold in an off-market deal for $38 million, up from the $20.5 million the seller paid for it in 2019, according to public records. The identities of both the buyer and the seller were shielded by shell companies.

But one week after the deal closed, billionaire hedge funder Ken Griffin was revealed as the buyer in a Wall Street Journal report citing a person familiar with the transaction.

The unit adds to Griffin’s real estate spread in Manhattan, including a piece of the storied property he already owns. The unit in the recent deal neighbors the 18-room unit he paid $45 million for in February 2025. Julia Koch, socialite and billionaire widow of David Koch, was the seller.

The Real Deal previously reported the price increase was likely due to a renovation, though the extent of the upgrade is unclear.

Construction at the apartment was referenced in a 2019 lawsuit over an alleged injury caused by work in the unit, at the time owned by the seller, an entity known as the E71 Trust. Court documents show the proposed work on the apartment was estimated to cost between $6 million and $6.5 million.

The trust purchased Unit 4/5D from investor Peter Huang, who bought it in the 1970s. Huang sought to offload the apartment for just under $30 million in 2013, though it took six years and several price cuts to finally sell.

The apartment spans roughly 7,500 square feet, according to a StreetEasy listing, which was pulled from the portal in 2018. At the time, the apartment had five bedrooms, five bathrooms and three wood-burning fireplaces. It also featured a dining room, chef’s kitchen and private elevator landing.

The Rosario Candela-designed building rose to prominence after housing members of the country’s wealthiest and most prominent families, including John D. Rockefeller Jr. and Jackie Kennedy Onassis.

The property’s peak deals in recent years include one by another hedge funder, Israel Englander. He set the Manhattan record for a co-op sale price when he bought a duplex in the building for $71.3 million in 2014.

Griffin has made his own waves in the Big Apple’s market. In 2019, he closed on a record deal for a massive penthouse at 220 Central Park South. He paid $238 million for the unit, below the original asking price but still a record for the United States.

Griffin’s other homes include a $122 million London mansion near Buckingham Palace, a Hamptons estate he bought from Calvin Klein for $84.4 million, a $107 million estate in Miami’s Coconut Grove neighborhood and land in Palm Beach that has cost Griffin more than $450 million.