President Donald Trump has more billionaires in his administration than any previous president, with at least nine. He counts plenty of billionaires as friends or fans: 16 visited him at Mar-a-Lago between the election and inauguration. Meta CEO Mark Zuckerberg reportedly just went to the White House on Wednesday following a Trump-Zuck White House meeting in early February.

But having a pro-business, pro-capitalism president who is also a billionaire hasn’t turned out very well so far for the members of the three-comma-club. From January 20 through Thursday March 13, the S&P 500 index fell 7.9%, while the tech-heavy Nasdaq index tumbled 11.8%. That downturn hit the country’s richest people in a big way: collectively, American billionaires are now $415 billion poorer, Forbes calculates.

By contrast the S&P 500 inched up 2.4% and the Nasdaq down 1% in the same period following Joe Biden’s inauguration. Over that same timespan, U.S. billionaires got $153 billion richer–a 3.6% increase.

Among the factors driving stocks lower: Trump’s on-again, off-again decisions on imposing tariffs on Canada and Mexico. That has created uncertainty–something that corporate leaders abhor. Plus, the new 25% tariffs that Trump placed on all steel and aluminum imports earlier this week look to be setting off a trade war, with the E.U. planning to launch its own tariffs on U.S. goods on April 1. Adding to the concerns: in early March the Atlanta Fed predicted a 2.8% contraction in economic growth for the first quarter–in what’s being dubbed a “Trumpcession.”

No billionaire has been hit as hard as Trump’s right hand man, Elon Musk. On January 20, the world’s richest person was worth $434 billion. Since then, reports have emerged of dramatic declines in Tesla car sales in the first two months of 2025 in Germany, China and Australia; analysts at JPMorgan cut their forecast for first quarter 2025 deliveries of Tesla vehicles by 20% to 355,000, the lowest since the third quarter of 2022. Meanwhile, protests against Tesla and Musk have erupted across the country at Tesla dealerships; while some are peaceful, others have included incidents of vandalism.

Amid it all, shares of Tesla have plunged 43% since the inauguration. That in turn erased $104 billion from Musk’s fortune, which was $330 billion after the stock market closed on Thursday, per Forbes estimates. Despite the 24% drop in his net worth, he has held onto his spot as No. 1 wealthiest on the planet.

Ross Mayfield, an investment strategist at Baird Private Wealth Management, doesn’t believe this hit to Musk’s wealth is surprising, or has much to do with Musk’s multiple roles of late. “I don’t think Musk’s place in the [Trump] administration is probably helping… but I don’t think that’s the primary driver. If we’re heading towards an economic slowdown, autos and cyclicals get hit the hardest, and autos are also really exposed to cross-border trade and tariffs,” Mayfield said.

The market rout has also hit several additional tech stocks hard. The once high-flying Magnificent 7–Tesla, Nvidia, Alphabet, Amazon, Meta, Apple, and Microsoft–have collectively lost more than $1.5 trillion of their market value since Jan. 20 amid concerns about economic weakness.

The leaders of several of those companies, including Amazon’s Jeff Bezos, Google (now Alphabet) cofounder Sergey Brin, and Meta’s Zuckerberg, all attended Trump’s inauguration and were given prominent placement among the attendees at the Capitol. These tycoons are now all among those whose fortunes have plunged the most since that celebration.

Here are the 20 U.S. billionaires who lost the most since January 20, 2025: (Net worths are as of market close on Thursday, March 13):

This article was originally published on forbes.com and all figures are in USD.

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