Key Takeaways
- • Ken Griffin, founder and CEO of Citadel, paid $38 million for a duplex apartment at 740 Park Avenue in an off-market transaction this month, acquiring the unit adjacent to an apartment he purchased in 2025 for $45 million from Julia Koch.
- • The newly acquired duplex, last publicly listed in 2018 at $22.5 million, contains approximately 7,500 square feet across five bedrooms with 41 windows, 21 closets, and three fireplaces; the seller acquired it through a trust in 2019 for $20.5 million.
- • Griffin's consolidated Park Avenue holdings now position him as a dominant player in one of Manhattan's most exclusive residential buildings, which has historically housed old-money aristocracy and remains highly sought despite softening demand for trophy co-ops citywide.
- • The acquisition reflects Griffin's broader ultra-prime real estate strategy, complementing his existing $238 million 2019 purchase of a penthouse at 220 Central Park South (the highest-priced U.S. residential sale on record) and additional holdings valued at over $1 billion across Miami, Palm Beach, Southampton, and London.
Summary
Ken Griffin has expanded his Manhattan real estate footprint with the acquisition of a $38 million duplex at 740 Park Avenue, completing an off-market transaction this month. The unit sits directly adjacent to an apartment Griffin purchased in 2025 for $45 million from Julia Koch, widow of industrialist David Koch, consolidating his presence within the prestigious cooperative building.
The duplex, which last appeared on the open market in 2018 with a $22.5 million asking price, encompasses approximately 7,500 square feet across five bedrooms. The unit features 41 windows, 21 closets, three wood-burning fireplaces, a library, formal dining room, private elevator vestibule, and a grand foyer with sweeping curved staircase. The previous owner acquired the unit through a trust structure in 2019 for $20.5 million, representing a significant appreciation over the seven-year holding period.
740 Park Avenue, constructed around 1930 by James T. Lee (grandfather of Jacqueline Kennedy Onassis), maintains its position as Manhattan's most coveted cooperative address. The building's roster has included cosmetics heir Ronald Lauder and hedge fund billionaire Israel Englander, alongside generations of New York's established wealth. Despite broader softening in trophy co-op demand across the city, the building continues to command premium pricing and selective demand among ultra-high-net-worth buyers.
Griffin's strategic consolidation of adjacent units at 740 Park Avenue aligns with his broader ultra-prime residential acquisition strategy. His portfolio includes a $238 million penthouse purchase at 220 Central Park South in 2019—the highest-priced residential transaction in U.S. history—along with significant holdings in Miami, Palm Beach, Southampton, and London, including a £95 million ($122 million equivalent) mansion at 3 Carlton Gardens near Buckingham Palace. The precise intent for the newly acquired Park Avenue duplex remains undisclosed.
The duplex, which last appeared on the open market in 2018 with a $22.5 million asking price, encompasses approximately 7,500 square feet across five bedrooms. The unit features 41 windows, 21 closets, three wood-burning fireplaces, a library, formal dining room, private elevator vestibule, and a grand foyer with sweeping curved staircase. The previous owner acquired the unit through a trust structure in 2019 for $20.5 million, representing a significant appreciation over the seven-year holding period.
740 Park Avenue, constructed around 1930 by James T. Lee (grandfather of Jacqueline Kennedy Onassis), maintains its position as Manhattan's most coveted cooperative address. The building's roster has included cosmetics heir Ronald Lauder and hedge fund billionaire Israel Englander, alongside generations of New York's established wealth. Despite broader softening in trophy co-op demand across the city, the building continues to command premium pricing and selective demand among ultra-high-net-worth buyers.
Griffin's strategic consolidation of adjacent units at 740 Park Avenue aligns with his broader ultra-prime residential acquisition strategy. His portfolio includes a $238 million penthouse purchase at 220 Central Park South in 2019—the highest-priced residential transaction in U.S. history—along with significant holdings in Miami, Palm Beach, Southampton, and London, including a £95 million ($122 million equivalent) mansion at 3 Carlton Gardens near Buckingham Palace. The precise intent for the newly acquired Park Avenue duplex remains undisclosed.
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