Even one of President Donald Trump's most vocal backers is wary of his tariff plan. 

Bill Ackman, the billionaire CEO of hedge fund Pershing Square and one of Trump's most fervent supporters on Wall Street, on Sunday criticized the president's "massive and disproportionate tariffs" on key U.S. trading partners and urged Trump to call a "90-day time out" to allow for negotiations. 

"Business is a confidence game. The president is losing the confidence of business leaders around the globe," Ackman posted to X on Sunday evening. "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." 

'Economic Nuclear War'

Ackman equated Trump's reciprocal tariffs—including a 20% levy on imports from the 澳洲幸运5官方开奖结果体彩网:European Union, 46% on Vietnamese goods, and 24% on Japanese products—with declaring "ecღonomic nuclear war on every country in the world," and warned the move would obstruct investment in the U.S. and cause lasting damage to America’s reputation on the world stage. 

In separate posts Sunday evening and Monday morning, Ackman placed blame for the tariff plans squarely on the president's advisors. "I just figured out why @howardlutnick is indifferent to the stock market and the economy crashing," he wrote late Sunday, referring to Commerce Secretary and former Cantor Fitzgerald CEO Howard Lutnick. "He and Cantor are long bonds. He profits when our economy implodes," Ackman wrote. 

National Economic Council Director Kevin Hassett criticized Ackman on Fox News on Monday morning, saying, "I would urge everyone, especially Bill, to ease off the rhetoric a little bit. ... The idea that it's gonna be a 'nuclear winter' or something like that is completely irresponsible rhetoric."

Ackman Softens Lutnick Comments Monday

Ackman softened his comments on Lutnick Monday morning, writing that "It was unfair of me to lash out at @howardlutnick. I don't think he is pursuing his self interest… I am just frustrated watching what I believe to be a major policy error occur after our country and the president have been making huge economic progress that is now at risk due to the tariffs."

But Ackman continued to push back on the tariff plans. "The formula used by the administration to calculate tariffs made other nations’ tariffs appear four times larger than they actually are," he wrote Monday morning, citing research from the American Enterprise Institute, a right-leaning think tank. "The President's advisors need to acknowledge their error before April 9th and make a course correction before the President makes a big mistake based on bad math."