Billionaire investor Bill Ackman is sounding the alarm that Mayor Zohran Mamdani's rent freeze, pied-à-terre tax, and anti-development policies will drive capital and jobs out of New York City, a warning backed by early signs the tax is already hitting far more homeowners than promised.
Ackman, the founder and CEO of Pershing Square Capital Management, laid out his case in a wide-ranging interview with Fortune published Wednesday. He pointed to the New York City Rent Guidelines Board's June vote to freeze rents on one- and two-year leases for rent-stabilized apartments, called the mayor's broader economic vision a recipe for decline, and argued that the city's housing crisis is a product of bad progressive policy, not capitalism.
His bluntest line landed without hedging. Ackman told Fox Business:
"The answer isn't socialism, socialism is a disaster."
FOX Business reported that Mamdani could not immediately be reached for comment.
Ackman's central argument is straightforward: when government makes it impossible for landlords to recover renovation costs, landlords stop renovating, and stop renting. He estimated that roughly 60,000 apartments have already been pulled off the New York City market for exactly that reason.
He framed the rent freeze as an accelerant poured on an existing fire:
"It's so high because left-wing mayors have made it very difficult for developers to build here, [and Mamdani], by freezing rents, is just going to make the problem worse."
And he drew a direct line between regulation and vacancy:
"If you make it hard to build where people want to live, and you don't let landlords recover renovation costs, they'll pull units off the market."
Ackman contrasted New York with Austin, Texas, where increased construction helped bring rents down, the kind of market-driven outcome that a friendlier regulatory environment can produce. The implication is plain: New York's affordability crisis is not some mystery. It is the predictable result of policies that punish building and reward stagnation.
Ackman's warnings do not exist in a vacuum. As the New York Post reported, Mamdani dismissed the entire advisory board of the Mayor's Fund to Advance New York City, removing executives from Blackstone, Citigroup, and major real estate firms. That board was not decorative. The Mayor's Fund has raised over $100 million for families of 9/11 rescue workers and $54.5 million during COVID, money that flowed through private-sector relationships the mayor just severed.
Clearing out the advisory board of a philanthropic body that depends on Wall Street and real estate donors sends a signal. It tells the business community that this administration views their participation as a liability, not an asset. Ackman's response was pointed:
"Watch what happens to New York City if Mamdani succeeds in implementing these plans."
He went further, naming the kind of investment the city should be courting rather than repelling:
"You want people like Ken Griffin locating Citadel here, spending $250 million on an apartment, because that purchase makes a building economically viable, which creates construction jobs and brings in wealthy residents who pay taxes."
Griffin's $250 million apartment purchase, in Ackman's telling, is not a symbol of inequality. It is the anchor transaction that makes a luxury tower pencil out financially, generating union construction jobs, property tax revenue, and a base of high-income residents who fund city services. Drive those buyers away, and the math collapses for developers and the city budget alike.
Ackman has long criticized New York City's pied-à-terre surcharge, which targets certain high-value properties not used as an owner's primary residence. But the scale of the policy's overreach is now becoming clear. Mark Penn, writing in a Fox News opinion column, reported that the New York City Department of Finance initially sent tax notices to 960,000 property entries, more than thirty times the 31,000 non-resident owners the city claimed it was targeting.
Co-ops and condos with assessed values over $1 million qualify for the surcharge, which can reach up to 5% or more of market value annually. For a homeowner sitting on a million-dollar condo, a figure that buys modest square footage in much of Manhattan, that could mean an additional $50,000 per year in taxes. Penn described the dynamic bluntly:
"Imposing steep surcharges on secondary condo owners could chill the broader housing market, reduce demand from out-of-town buyers and ultimately drag down property values across the board."
The pattern Penn identified is familiar to anyone who has watched progressive tax policy expand past its original target. A tax sold as a levy on absentee billionaires lands on retirees who kept a family apartment, on small investors who own a rental unit, on middle-class homeowners who never imagined they would be classified alongside hedge fund managers. Penn called it out directly:
"This is how creeping socialism works: Politicians advertise that they are going after only those greedy out-of-town billionaires, while creating a sprawling administrative property database that exposes personal details of thousands of everyday homeowners."
Ackman did not limit his critique to housing. He turned to energy policy, another area where New York's progressive leadership has imposed costs on residents while congratulating itself for ideological purity.
He laid the blame in specific terms:
"Why are energy costs so high in New York State? Because we've shut down nuclear power, it takes 15 years to get a pipeline approved, and we've banned fracking, so we're importing natural gas from Pennsylvania."
New York banned fracking, shut down nuclear capacity, and created a permitting environment so hostile that pipeline approvals stretch across a decade and a half. The result is that the state imports the same natural gas its own geology could produce, but at a higher cost, routed through another state's infrastructure. Residents and businesses pay the markup. Ackman's summary was brief:
"That's just bad policy, and we can fix a lot of it with better policy."
Ackman also flagged California's Proposition 40 as a cautionary tale for New York. The measure could impose a one-time tax equal to 5% of the net worth of billionaires who were California residents on January 1, 2026. Ackman was skeptical of the "one-time" label:
"Look at what's happening in California right now with the wealth tax, they say it's 'one time,' but it's never one time."
His concern is that New York, under Mamdani's leadership, is moving in the same direction, creating a policy environment where wealthy residents and the businesses they run face escalating, unpredictable tax burdens. He singled out Elon Musk as the type of business leader cities should compete to attract, not repel:
"You don't want to discourage people like Elon Musk from locating their businesses here."
Capital is mobile. People with resources relocate. This is not a theory, it is the documented experience of every high-tax jurisdiction that pushed too hard and watched its revenue base walk out the door.
For all his criticism of Mamdani's agenda, Ackman did not dismiss the frustration that fuels progressive politics. He acknowledged a real problem, one he framed in market terms rather than ideological ones:
"One of our biggest challenges as a country is that almost half the country isn't participating in the growth in value created by capitalism, the stock market."
He went further, connecting economic exclusion to political radicalism:
"Part of that is people feeling left behind, wages can't compound as quickly as stocks, so everyone needs to participate in the market to believe in capitalism."
That is a candid admission from a man who runs a major hedge fund. The answer to inequality, in Ackman's view, is broader participation in markets, not the kind of government-imposed rent freezes, wealth taxes, and development restrictions that Mamdani favors. One approach builds wealth. The other redistributes a shrinking pie.
Mamdani may believe he is standing up for working New Yorkers. But when 60,000 apartments sit empty, tax notices land on nearly a million properties instead of 31,000, and the city's biggest investors start warning publicly that the math no longer works, the people who pay the price are not billionaires. They are the renters, workers, and small property owners who cannot afford to leave.
