Ken Griffin's hedge fund just told New York City's mayor, in blunt terms, what happens when you single out the people writing the checks. A companywide email from Citadel's chief operating officer called Mayor Zohran Mamdani's viral video about Griffin's Manhattan penthouse "shameful", and warned that a massive Midtown redevelopment project worth more than $6 billion may not move forward.
The email, sent Thursday afternoon by COO Gerald Beeson and obtained by the New York Post, laid out the stakes in plain dollar figures: 6,000 construction jobs, more than 15,000 permanent jobs, and billions in economic activity, all tied to the planned redevelopment of 350 Park Avenue in Midtown. The phrase that should keep City Hall up at night: "if we move forward."
The confrontation began last week, when Mamdani, a 34-year-old Democratic socialist who pledged during his campaign to ramp up taxes on the rich, stood in front of Griffin's 24,000-square-foot property at 220 Central Park South and announced what he called a pied-à-terre tax. Griffin purchased the property in 2019 for $238 million, a figure S1 describes as the most expensive home sale in the country at the time.
In his April 15 video, Mamdani declared victory on the tax proposal. His language left little room for ambiguity about the target:
"We've secured a pied-à-terre tax. This is an annual fee on luxury properties worth more than $5 million, whose owners do not live full-time in the city. Like for this penthouse, which hedge fund CEO Ken Griffin bought for $238 million."
The mayor's broader agenda includes free childcare, free buses, and city-owned grocery stores, all funded, he says, by soaking the wealthy. The pied-à-terre tax requires approval from state lawmakers in Albany. RealClearPolitics reported that the proposal, approved by Democrats in Albany, would raise Griffin's annual property tax on his New York City residence from about $841,000 to roughly $3 million.
Gov. Kathy Hochul, who earlier this year had tried to win back wealthy New Yorkers fleeing the state by calling for "smart" tax policy and "not just taxing for the sake of taxing," flipped last week. She backed the mayor's luxury second-home tax after initially resisting it.
That reversal is worth pausing on. Hochul spent months signaling restraint, then folded the moment Mamdani applied political pressure. The governor's about-face follows a pattern of stalled negotiations between the two that have defined the early months of Mamdani's administration.
Citadel's response did not mince words. Beeson's email accused the mayor of displaying "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 laid out the firm's receipts. Over the past five years, Citadel principals and team members, including those who do not live in New York City, have paid nearly $2.3 billion in city and state taxes. Griffin personally has contributed $650 million in charitable donations supporting New York City residents.
Then came the warning about 350 Park Avenue. Beeson wrote:
"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. The project, if we move forward, will entail more than $6 billion dollars of spending."
That conditional, "if we move forward", is the kind of language corporate executives use when they want elected officials to understand that capital is mobile. It is not a bluff. It is a reminder.
Beeson also took direct aim at Mamdani's decision to name Griffin specifically in the video. "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 COO wrote. Mamdani's office did not immediately respond to the Post's request for comment.
This is not the first time Griffin has signaled that bad governance drives real consequences. In 2022, he announced he was moving Citadel's headquarters from Chicago to Miami. His reasons were not subtle.
In November 2025, speaking with Fox News' Bret Baier, Griffin described what drove him out of Illinois:
"I've lived in a failed city-state. I lived in Chicago for 30-some years. I had two colleagues who had bullets fly through their cars. I had 25 bullet holes in the front of my building where I lived. You can't live in a city awash [with] violent crime."
Forbes estimates Griffin's net worth at $50 billion. His primary residence is now near Miami. The pattern is clear: when cities make wealthy residents feel targeted or unsafe, those residents leave, and they take their tax revenue, their jobs, and their philanthropy with them.
That pattern should concern anyone who cares about New York's fiscal health. Mamdani's broader tax agenda has already drawn sharp criticism for its potential to accelerate the flight of high earners from the city.
Beeson was not alone in criticizing the mayor. Billionaire hedge fund manager Bill Ackman posted on X shortly after the video's release, warning that Mamdani's approach could backfire badly.
"We should be applauding Ken for spending $238 million in NYC, not attacking him for doing so. 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."
CNBC anchor Sara Eisen made a similar point in a social media post, noting that Griffin "employs thousands of people in NYC" and is "investing billions more and creating thousands more jobs." She added that "making him feel unwelcome and demonizing him seems risky."
Eisen drew the comparison explicitly: "Meantime Miami is welcoming him and his firm, with the massive jobs, investment and tax revenue he's bringing." The RealClearPolitics commentary echoed this concern, arguing that higher taxes on wealthy nonresident property owners could shift investment toward cities like Miami, Palm Beach, Austin, and Dallas.
The broader context of Mamdani's governing style only sharpens the picture. His administration has already forced out senior officials and pursued sweeping policy changes within weeks of taking office.
Mamdani's pitch is simple: make the rich pay for free services. The problem is that the rich can leave. Griffin already proved that once, and Beeson's email makes clear the firm is weighing whether New York still deserves the investment.
Consider the numbers side by side. Mamdani wants to raise Griffin's annual property tax from roughly $841,000 to about $3 million, a gain of roughly $2.2 million per year for the city. Citadel says the 350 Park Avenue project alone would generate $6 billion in spending, 6,000 construction jobs, and more than 15,000 permanent positions. The firm and its people have paid $2.3 billion in city and state taxes over five years.
That is the trade-off Mamdani is making: a few million more in annual tax revenue from one penthouse, in exchange for potentially losing billions in investment, tens of thousands of jobs, and a tax base that dwarfs the new levy. It is the kind of math that looks good in a campaign video and falls apart on a spreadsheet.
Meanwhile, Mamdani continues to push tax hikes as the centerpiece of his governing agenda, framing the debate as one of fairness rather than fiscal reality.
Richard Porter, quoted in the RealClearPolitics commentary, put it this way: "Ken Griffin loves New York, but since the 2025 mayoral election it's turned into an unrequited love."
You can only make someone feel unwelcome so many times before they take you at your word. And when they go, they don't leave behind free childcare or city-owned grocery stores. They leave behind a hole in the budget that no pied-à-terre tax can fill.
