A high-profile public feud has broken out between New York Mayor Zohran Mamdani and billionaire hedge fund titan Ken Griffin over Mamdani’s signature policy initiative: a sweeping plan to raise taxes on the city’s wealthiest residents and ultra-luxury properties.
Griffin, founder and CEO of Citadel, who holds the deed to the most expensive residential property ever purchased in the United States, slammed Mamdani’s proposal and the mayor’s public campaign for it during an appearance at Tuesday’s Milken Institute Global Conference in Beverly Hills, California. The billionaire called a video Mamdani filmed outside his $238 million Manhattan penthouse earlier this year “creepy and weird,” arguing that the stunt stokes dangerous political polarization that could lead to violence. He pointed to the fatal shooting of UnitedHealthcare CEO Brian Thompson near the property as evidence that public targeting of high-profile individuals creates unacceptable security risks.
“Anything that creates, like an agitation, in the extremist on either side of the aisle is a frightening dynamic,” Griffin told attendees. In response to his criticism, Griffin confirmed he would accelerate his existing shift of business operations from Manhattan to Miami, saying Mamdani’s agenda sends a clear message that achievement is not welcome in New York City. “Mamdani was making it really clear: New York doesn’t welcome success,” Griffin said. “I will double down focusing on Miami to grow my business interests rather than Manhattan.”
The contentious video in question was filmed in April to align with the U.S. annual tax filing deadline, as part of Mamdani’s push to introduce a new annual pied-à-terre tax. This levy would apply to non-resident-owned properties valued above $5 million, a policy explicitly designed to target wealthy individuals who park large sums of wealth in New York City real estate without maintaining primary residency or paying full local taxes. Standing directly outside the building that houses Griffin’s penthouse, Mamdani used the 2019 purchase of that unit – which still holds the record for the most expensive home ever bought in the U.S. – as a prominent example of the gap the new tax would close. Mamdani projects the pied-à-terre tax alone will generate at least $500 million in new annual revenue for the city, while broader tax increases on corporations and the wealthy could raise up to $9 billion to fund the mayor’s policy agenda. That broader package includes lifting the city’s corporate tax rate from 7.25% to 11.5%.
In an official statement provided to the Wall Street Journal following Griffin’s comments, Mamdani’s press secretary Joe Calvello pushed back against the billionaire’s criticism while acknowledging his economic impact on New York. Calvello clarified that the mayor supports all successful New York-based entrepreneurs and business leaders, noting that Griffin himself is a major employer within city limits who contributes meaningfully to the local economy. However, Calvello reaffirmed the administration’s core position that the city’s current tax structure is fundamentally unfair and broken, requiring targeted reform to ask higher contributions from the wealthiest property owners.
Mamdani’s push for progressive wealth taxation has deeply divided public and political opinion in New York, with critics echoing Griffin’s warning that steep tax hikes will push wealthy individuals and major employers to relocate to lower-tax jurisdictions like Florida, ultimately reducing the city’s total tax revenue and harming local economic growth. Requests for additional comment from the mayor’s office were not immediately answered.