Wall Street leaders issued fresh warnings amid growing risks caused by the sweeping U.S. tariffs, with JPMorgan Chase CEO Jamie Dimon saying they could have lasting negative consequences, while fund manager Bill Ackman said they could lead to an "economic nuclear winter."
In Dimon's annual letter to shareholders, published on Monday following a rout last week that wiped off trillions of dollars from global stock markets, he expressed concern about how the tariffs would impact America's long-term economic alliances.
"The economy is facing considerable turbulence (including geopolitics)," Dimon wrote. "We are likely to see inflationary outcomes ... Whether or not the menu of tariffs causes a recession remains in question, but it will slow down growth."
Stocks in Asia, Europe and on Wall Street plunged on Monday as investors braced for more losses.
Dimon's comments come after billionaire Ackman, who endorsed Donald Trump's run for president, said business leaders were losing confidence in Trump. Ackman also called on the president to pause and renegotiate trade deals.
If the tariffs are imposed this week, "we are heading for a self-induced, economic nuclear winter," Ackman wrote in a post on X. They would stymie business investment and consumer spending and "severely damage" the U.S.' reputation for years, he wrote.
JPMorgan's economists raised the risk of a U.S. and global recession this year to 60% from 40% after Trump unveiled the steepest trade barriers in more than 100 years last week. When asked on Sunday about falling markets, Trump said sometimes it is necessary to take medicine to fix something.
Dimon, 69, has run the largest U.S. bank for 19 years and is one of the most prominent voices in corporate America.
"The quicker this issue is resolved, the better because some of the negative effects increase cumulatively over time and would be hard to reverse," the CEO wrote.
He listed the potential negatives of the tariffs and trade war, including persistent inflation, high fiscal deficits, elevated asset prices and volatility.
Dimon also expressed concern that the tariffs would draw retaliation by other countries and affect economic confidence, investments, capital flows, corporate profits and the dollar.
JPMorgan will report its first quarter results on Friday. The lender earned a record annual profit last year.
Dimon often weighs in on government policies, and has been consulted by officials in times of crisis.
His name was floated for senior economic roles in government during the 2024 presidential campaign, including Treasury secretary, but he stayed put at the bank.
Tariffs also raise questions about the direction of interest rates, Dimon said. While rates have declined recently because of the weaker dollar, the prospect of slower growth and declining risk appetite could cause rates to rise, he said, referring to the stagflation of the 1970s.
Expectations for modest U.S. growth, known as a soft landing, could also be derailed.
"We enter this time of uncertainty with high equity and debt prices, even after the recent decline ... markets still seem to be pricing assets with the assumption that we will continue to have a fairly soft landing. I am not so sure," Dimon wrote.
