MacArthur Fund

Day-to-day investment and operational decisions are made by the three principals — David Katz, Howard Katz, and Philip Katz — alongside partners Andrew Katz, Gabriel Katz, Jeremy Katz, Robert Loffredo, and Robert Doster, per the firm's own website. No external investment committee or non-family CIO is disclosed.

The firm does not publicly describe a deal-sourcing channel beyond its in-house team and multi-decade family relationships in New York and the Northeast. Given 70 years of continuous operations and a portfolio built through direct acquisition, ground-up development, and long-term land holds, sourcing likely flows through broker networks, family industry contacts, and repeat corporate relationships such as build-to-suit tenants.

MacArthur operates as a single-family office but functions in practice like an integrated owner-operator-developer. It acquires land, pursues entitlements and rezoning, self-performs or oversees ground-up construction, and retains long-term ownership of operating assets — with no indication of third-party capital or fund vehicles on its website.

The firm's entire known portfolio consists of directly owned real estate — commercial, residential, hotel, self-storage, and development sites — with no publicly disclosed fund commitments or LP positions in external real estate funds.

MacArthur's portfolio is concentrated in New York City (Manhattan, Brooklyn, the Bronx) and the Northeast (New Hampshire, Pennsylvania), with a secondary Sun Belt footprint in Florida, Georgia, and South Carolina. The New Hampshire holdings include multiple build-to-suit office and industrial projects in Portsmouth.

The wealth originates from a fourth-generation family real estate business founded by Simon Katz, per the firm's website. The business has been building, owning, and operating property primarily in New York City for 70 years. No liquidity event — such as a sale of an operating company — is cited as the source of capital.

The firm's website does not reference any separate philanthropic foundation, donor-advised fund, or family charitable vehicle. If one exists, its structure and separation from the real estate operations are not publicly disclosed.