By: Daisy Fay Buchanan

Aquarian Holdings LP, a global financial powerhouse with $22 billion in assets under management, has signed a blockbuster lease for the 75,000-square-foot penthouse at 550 Madison Avenue—arguably Midtown Manhattan’s most prestigious office location. The three-level space sits atop the landmark Philip Johnson– and John Burgee–designed tower, famously known for its distinctive “Chippendale” top.

As the New York Post first reported, the deal brings the tower’s total occupancy to an impressive 96%.

The building, originally developed for AT&T in 1984 and later occupied by Sony, was purchased in 2016 by the Olayan Group for $1.4 billion. The Saudi-backed real estate investor then poured at least $300 million into modernizing the space. The extensive renovations included major overhauls of the office floors, a dramatic redesign of the lobby, and major infrastructure upgrades—all completed under the oversight of the city’s Landmarks Preservation Commission. A glass-canopied pedestrian arcade and garden, spanning East 55th to East 56th Streets, was also added to breathe new life into the iconic tower.

The NY Post exclusively reported that Aquarian’s new lease further solidifies 550 Madison’s resurgence as a magnet for elite tenants. The tower has already attracted marquee firms like insurance giant Chubb Ltd., which took 240,000 square feet, and private equity heavyweight Clayton Dubilier & Rice, with 144,000 square feet. French luxury house Hermès also signed for 72,000 square feet for its U.S. headquarters.

Only two spaces reportedly remain: the 22nd floor and a small prebuilt section on the 34th floor. On the retail front, acclaimed restaurateur Simon Kim’s Gracious Hospitality Group has leased the northern ground-floor corner, leaving just the southern retail corner up for grabs.

Aquarian, led by founder Rudy Sahay, is relocating from its current home at 40 Tenth Avenue in Chelsea. Sahay, a seasoned investment executive, previously co-founded 54 Madison Partners and was a founding member of Guggenheim Partners. Under his leadership, Aquarian has expanded aggressively, including forming a joint venture with Raven Capital Management, an investment firm focused on the music and entertainment industries. The firm also recently launched Aquarian Insurance Holdings, which unifies its reinsurance and retail insurance operations under one umbrella.

As NY Post first reported, the leasing success of 550 Madison has positioned it as a barometer for Manhattan’s office market recovery. Since late 2021, more than 300,000 square feet in the building have leased at rates exceeding $100 per square foot—a benchmark few properties in the city have matched, particularly in a post-pandemic market.

The deal with Aquarian underscores not only the appeal of 550 Madison but also the broader trend of deep-pocketed financial firms snapping up high-end, amenity-rich office space in central locations. With its blend of historic architecture and cutting-edge renovation, 550 Madison is proving that trophy properties can still command top-tier demand—even in a time of hybrid work and corporate downsizing.

As the NY Post exclusively reported, the lease is a major win for both Aquarian and the Olayan Group, further cementing 550 Madison’s status as Midtown’s crown jewel.