Billionaire Ken Griffin, the founder of Citadel, is reportedly livid with New York City (NYC) Mayor Zohran Mamdani for using his property to promote a new tax.
On April 15, aka Tax Day, Mamdani introduced a “pied-a-terre” tax on barely used second properties that the rich own in NYC.
“This is an annual fee on luxury properties worth more than $5 million whose owners do not live full-time in the city,” Mamdani said while speaking right outside one of Griffin’s penthouses. “Like for this penthouse, which hedge-fund CEO Ken Griffin bought for $238 million.”
Happy Tax Day, New York. We’re taxing the rich. pic.twitter.com/Wky2LFXC9W
— Mayor Zohran Kwame Mamdani (@NYCMayor) April 15, 2026
Griffin was not pleased by the disrespect from the communist mayor.
In an email sent two days later to Citadel employees, CEO Gerald Beeson suggested that Griffin may potentially not move forward with plans for a huge Midtown construction project.
“We are about to commence the redevelopment of 350 Park Avenue, creating 6,000 highly paid construction jobs and supporting the creation of more than 15,000 permanent jobs in mid-town New York,” he wrote, according to The Wall Street Journal. “The project—if we move forward—will entail more than $6 billion dollars of spending.”
Turning to Mamdani, Beeson then opened fire.
“It is shameful that he used Ken’s name as the example of those who supposedly aren’t carrying their fair share of the burdens associated with New York City’s often costly and wasteful spending,” he wrote.
“In doing so, the mayor has once again manifested the ignorance and disdain of the elite political class towards those who have been consistently committed to building one of the greatest cities in the world,” he added.
Beeson continued by noting that Citadel “principals and team members (including nonresidents) have paid nearly $2.3 billion dollars in city and state taxes” during the past five years. He also touted Griffin’s direct contribution of $650 million in charitable gifts to NYC.
“We have nearly 2,500 colleagues who have chosen to build their careers here,” the Citadel CEO wrote. “We understand that our hard work and success will, on occasion, make us targets for political rhetoric. But it should not diminish the pride we take in building firms that will continue to help New York City thrive for decades ahead.”
News of Griffin’s anger resonated with fellow billionaire Bill Ackman:
Non-residents who spend millions of dollars on NYC apartments help drive NYC’s economy. Most of the profit in condominium development is in the penthouses. The Ken Griffins of the world make NYC high end development viable, driving high-paying construction, brokerage, legal,… https://t.co/7Iv6UhGzdf
— Bill Ackman (@BillAckman) April 16, 2026
“We should be applauding Ken for spending $238 million in NYC, not attacking him for doing so,” Ackman wrote in a tweet. “Importantly, non-resident owners of NYC apartments who leave their apartments vacant for much of the year are not a burden to NYC schools, services, or other resources while they drive growth in retail sales, restaurants, theater, and other important drivers of our economy.”
“Ken’s company is a major employer in NYC of very high paying jobs which drive a considerable amount of our tax base. We wouldn’t want him to move even more employees to Miami,” he added.
This isn’t Griffin’s first foray with the radicalized, confiscatory left. In 2022, he relocated Citadel from the leftist state of Illinois to the right-wing state of Florida after clashing repeatedly with far-left Illinois Gov. J.B. Pritzker.
The consequences of his decision have been devastating for the Chicago area.
“According to a 2024 report from Crain’s Chicago Business, Griffin had donated more than $650 million to various causes throughout Chicago,” New York magazine notes. “His philanthropy has since shifted to Florida, where he has distributed more than $300 million since moving.”
He’s specifically relocated to Miami, which at the time had the following Republican as its mayor:
We 100% are. NY/Chicago’s loss is our gain. Ken not only employs a lot of people in our ecosystem, he is a prolific philanthropist who has invested in everything from education to public spaces to helping the homeless. We value him and @Citadel https://t.co/cjW7wx7Yoa
— Francis X. Suarez (@FrancisSuarez) April 16, 2026
Its current mayor is, however, a Democrat.
