New York City Mayor Zohran Mamdani marked tax day by making good on one of his most prominent campaign promises, and he did it while outside hedge fund billionaire Ken Griffin’s front door—and the Citadel CEO worth over $51 billion did not like it one bit.
“When I ran for mayor, I said I was going to tax the rich,” Mamdani said in the one-minute clip. “Well, today we’re taxing the rich.”
But a week later, Griffin’s COO at Citadel, Gerald Beeson, hinted the company might not move forward with a massive undertaking in a Midtown construction project.
Later in the letter, Beeson called out the mayor personally, for personally calling out Griffin. “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,” the email said, according to the Journal. “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.”
“We have nearly 2,500 colleagues who have chosen to build their careers here,” Beeson wrote in the letter, the Journal reported. “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.”
The pied-à-terre tax, which is backed by Gov. Kathy Hochul and still requires approval from the state legislature, would apply to one-to-three-family homes, condominiums, and co-ops worth over $5 million when the owner’s primary residence is outside New York City. Mamdani’s office estimates the tax would generate at least $500 million annually, with revenue directed toward free childcare, street cleaning, and neighborhood safety.
Mamdani said the tax would fix “a fundamentally unfair system.” “These units are sitting empty,” he said. “And even so, they’re able to reap the huge financial rewards of owning property in, dare I say, the greatest city in the world.”
“Non-residents who spend millions of dollars on NYC apartments help drive NYC’s economy,” wrote Ackman. “The Ken Griffins of the world make NYC high end development viable, driving high-paying construction, brokerage, legal, marketing, and other jobs in NYC. We should be applauding Ken for spending $238 million in NYC, not attacking him for doing so.”
A version of this story was published on Fortune.com on April 16, 2026.
