"Economic nuclear winter" at risk without immediate tariff pause, Ackman says

The world faces an "economic nuclear winter" if President Trump doesn't immediately pause his sweeping reciprocal tariffs, hedge fund manager Bill Ackman said Sunday night.Why it matters: The billionaire Ackman, a staunch Trump supporter, put the market's fears about the fate of the global economy in the starkest terms possible.What they're saying: "The President has an opportunity on Monday to call a time out and have the time to execute on fixing an unfair tariff system. Alternatively, we are heading for a self-induced, economic nuclear winter, and we should start hunkering down," Ackman wrote in a lengthy post to X."May cooler heads prevail."Zoom out: Ackman's Sunday post follows another Saturday where he suggested the world would be better off with a pause on Wednesday's reciprocal tariffs, warning of a "potentially severe" recession otherwise.Sunday's rhetoric, though, raised the stakes. Between the lines: Ackman's new post acknowledged the administration's position that decades of unfair trade practices by other nations disadvantaged the U.S.But he said the downsides of rushing into a tariff regime were far worse, framing the current moment as an "opportunity" for Trump to pause the tariffs for 90 days and negotiate.The alternative, he said, was that "business investment will grind to a halt, consumers will close their wallets and pocket books, and we will severely damage our reputation with the rest of the world that will take years and potentially decades to rehabilitate."Context: Ackman endorsed Trump last summer, shortly after an assassination attempt against the then-former president at a presidential campaign rally.In October, he made a lengthy case on social media for Trump as the better candidate.He later said he hoped Trump's victory would lead to the "implosion" of the Democratic Party.Go deeper: Trump tariffs based on massive error, conservative think tank says

The world faces an "economic nuclear winter" if President Trump doesn't immediately pause his sweeping reciprocal tariffs, hedge fund manager Bill Ackman said Sunday night.Why it matters: The billionaire Ackman, a staunch Trump supporter, put the market's fears about the fate of the global economy in the starkest terms possible.What they're saying: "The President has an opportunity on Monday to call a time out and have the time to execute on fixing an unfair tariff system.

Alternatively, we are heading for a self-induced, economic nuclear winter, and we should start hunkering down," Ackman wrote in a lengthy post to X."May cooler heads prevail."Zoom out: Ackman's Sunday post follows another Saturday where he suggested the world would be better off with a pause on Wednesday's reciprocal tariffs, warning of a "potentially severe" recession otherwise.

Sunday's rhetoric, though, raised the stakes. Between the lines: Ackman's new post acknowledged the administration's position that decades of unfair trade practices by other nations disadvantaged the U.S.

But he said the downsides of rushing into a tariff regime were far worse, framing the current moment as an "opportunity" for Trump to pause the tariffs for 90 days and negotiate.The alternative, he said, was that "business investment will grind to a halt, consumers will close their wallets and pocket books, and we will severely damage our reputation with the rest of the world that will take years and potentially decades to rehabilitate."Context: Ackman endorsed Trump last summer, shortly after an assassination attempt against the then-former president at a presidential campaign rally.

In October, he made a lengthy case on social media for Trump as the better candidate.He later said he hoped Trump's victory would lead to the "implosion" of the Democratic Party.Go deeper: Trump tariffs based on massive error, conservative think tank says.