Castle Hook Partners, a Manhattan-based hedge fund manager, has committed to the top two floors of 625 Madison Ave., a new office skyscraper under development by Related Cos. in Midtown East. City property records, cited by the New York Business Journal, show that the firm has signed a long-term lease for the entire uppermost portion of the tower, positioning the hedge fund among the initial tenants at the property.
The lease runs for 15 years and includes options that could extend Castle Hook Partners’ occupancy for up to an additional 10 years. While financial terms and square footage for the lease were not disclosed, the commitment establishes a significant presence for the firm within the building and provides the developer with a notable early tenant at the top of the tower.
The office building at 625 Madison Ave. is planned to rise 53 stories and encompass approximately 860,000 square feet once completed. Related Cos. is currently developing the project, with construction scheduled to conclude in 2029. The engagement of Castle Hook Partners follows an earlier leasing milestone at the property that was announced at the beginning of the month.
At that time, Related Cos. reported that global investment firm General Atlantic had agreed to a five-floor lease totaling 150,000 square feet, making it the building’s anchor tenant. The General Atlantic commitment signaled initial momentum for the project, and the subsequent lease for the tower’s top two floors further advances the property’s preleasing profile ahead of its targeted completion.
The skyscraper is located along Madison Ave. between 58th and 59th Streets in Midtown East, a corridor known for its proximity to Central Park and a concentration of high-profile office properties. The tower has been designed by architecture firm Foster + Partners and is planned to feature Central Park views along with column-free floor plates and corners intended to provide flexible office layouts and open sight lines.
According to the project details, the building is being developed as an all-electric property and is targeting LEED Platinum certification, reflecting a focus on sustainable design and modern building systems. These design choices place the tower among a group of newer office projects that emphasize energy performance and high environmental standards as part of their appeal to tenants.
Related Cos. acquired the development site in 2024 and subsequently demolished the existing structure on the parcel. The prior building, completed in 1956, originally served as the headquarters for Nabisco and later became home to Related Cos.’ own corporate offices before being taken down to make way for the new tower. The redevelopment marks a transition from a mid-20th-century office property to a contemporary high-rise designed to compete in the current office leasing environment.
