NEW YORK (VINnews) — Billionaire investor Ken Griffin is threatening to reconsider a major $6 billion New York City development after Mayor Zohran Mamdani used his penthouse as a backdrop in a tax-the-rich campaign video.

Happy Tax Day, New York. We’re taxing the rich. pic.twitter.com/Wky2LFXC9W

— Mayor Zohran Kwame Mamdani (@NYCMayor) April 15, 2026

The clash escalated Thursday night, when The Wall Street Journal reported that a top Citadel executive warned internally the firm could rethink its level of investment in the city.

The dispute began after Mamdani filmed a viral video outside Griffin’s 24,000-square-foot residence at 220 Central Park South, promoting a proposed “pied-à-terre” tax on luxury second homes.

In a companywide email, Citadel Chief Operating Officer Gerald Beeson said the firm is preparing to redevelop 350 Park Avenue — a project expected to create about 6,000 construction jobs and more than 15,000 permanent positions — but cautioned: “The project — if we move forward — will entail more than $6 billion of spending.”

Griffin, who bought the penthouse for roughly $238 million in 2019 — the highest home sale in U.S. history — has long been critical of high-tax environments. His firm previously relocated its headquarters from Chicago to Miami.

Citadel also emphasized that its employees have paid billions in New York taxes in recent years, while Griffin has donated hundreds of millions to charitable causes.

The episode underscores growing friction between wealthy investors and progressive leaders, with concerns mounting that aggressive tax policies could push jobs, capital and major developments out of New York.