The total number of billionaires across the globe reached new heights in 2025, due partly to the soaring valuations of tech companies and rising stock markets, according to a new study by Swiss banking giant UBS .

Some 2,900 billionaires now control $15.8 trillion, up from about 2,700 billionaires with a cumulative wealth of nearly $14 trillion a year earlier. The number and wealth of billionaires as a whole were boosted by the second-highest number of new billionaires minted in a year—287—since UBS began tracking that figure in 2015. 

Only 2021, with its flood of government stimulus and low interest rates that boosted the prices of assets, saw a higher number of new billionaires created.

“You’ve seen this acceleration of billionaire growth, and it’s actually coming from all areas,” said John Mathews , UBS’s head of private-wealth management in the U.S., referring to the creation of new billionaires from both entrepreneurship and inheritance.

Also boosting wealth gains: a rising stock market over the 12 months ended April 4, 2025, the period covered by the study.

 The stock-market rout around President Trump’s so-called Liberation Day tariff announcement damped returns for the period, though the market has largely continued churning upward since.

The new, self-made billionaires created in 2025 were entrepreneurs in a range of fields. 

According to UBS, they include Ben Lamm , founder of Colossal Biosciences; Michael Dorrell , co-founder of infrastructure investment firm Stonepeak Partners; the Zhang brothers of Mixue Ice Cream and Tea in China; and crypto billionaire Justin Sun .

Ninety-one of the new billionaires inherited their wealth, including 15 members of two pharmaceutical families in Germany. “We’ve been talking about the great wealth transfer now for over a decade now, and you’re starting to see it come to fruition,” Mathews said. “I’d say we’re in the second inning of a nine-inning baseball game.”

He said much of the wealth would first pass to surviving partners, typically wives, before passing on to the next generation.

A recent analysis by Altrata, a wealth-intelligence firm, similarly showed growth in the number of billionaires around the world to record levels . Altrata estimated 3,508 individuals held $13.4 trillion in total wealth and said about a third were in the U.S. China came in second with 321 billionaires holding about 10% of the world’s wealth.

The UBS report includes information from a database maintained by UBS and PricewaterhouseCoopers that looks at billionaire wealth globally.

UBS also interviewed 87 billionaire clients for its 11th annual Billionaire Ambitions report and found that the appeal of North America as the best place to invest in the short term had decreased to 63%, from 81% a year earlier. 

The appeal of investing in other regions—Western Europe, Greater China, and Asia-Pacific excluding Greater China—picked up.

While Asian billionaires’ top worry for the next year was tariffs, a majority of U.S. billionaires were most concerned about inflation or geopolitics, according to the study.

Write to Juliet Chung at Juliet.Chung@wsj.com