The US risks 'economic nuclear war' if it doesn't scale back tariffs immediately, Bill Ackman says

• Billionaire hedge fund manager Ackman called for a pause on Trump's sweeping tariffs.
• "This is not what we voted for," Ackman wrote on X.
• The across-the-board tariffs could damage confidence and trust in the US for decades, he warned.

Billionaire hedge fund investor Bill Ackman is ringing the alarm over Washington's tariff spree, warning that President Donald Trump's policy must be delayed.

The Pershing Square founder backed President Donald Trump during the campaign but now says the trade war isn't what voters wanted. The administration needs to change course to avoid even more dire consequences, he said.

"If, on the other hand, on April 9th we launch economic nuclear war on every country in the world, business investment will grind to a halt, consumers will close their wallets and pocketbooks, and we will severely damage our reputation with the rest of the world that will take years and potentially decades to rehabilitate," the Pershing Square founder wrote on X.

Last week, Trump rolled out across-the-board duties at rates that shattered expectations, sending global markets into a tailspin. While Ackman said he does endorse reworking trade deals to advance US industry and job creation, indiscriminate and massive levies could devastate business confidence and slash global appetite for US investment.

Instead, Ackman is urging Trump to call a 90-day timeout to the tariffs on Monday, during which the president can negotiate and resolve any trade inequities.

Otherwise, the consequences of the trade war have already been deeply felt in the market. Since Wednesday's tariff announcement, the S&P 500 has tanked over 15% and is now in a bear market.

Odds of a recession have also spiked, bolstering chances of a 100 basis point interest rate reduction by the end of the year.

"The consequences for our country and the millions of our citizens who have supported the president — in particular low-income consumers who are already under a huge amount of economic stress — are going to be severely negative. This is not what we voted for," Ackman added.

In a separate post, Ackman emphasized that neither he nor Pershing Capital is set up to profit from a tariff pause.

He is not the first Wall Street heavy-hitter to speak up against the mounting trade war. Over the weekend, hedge fund manager Stanley Druckenmiller made a rare post on X citing his stance against tariffs that exceed 10%.