Fifteen years ago, the world’s billionaires collectively had $4.5 trillion.
By 2024, their wealth had more than tripled to $14.2 trillion.
Now, their combined wealth totals $20.1 trillion — an amount that is equivalent to nearly a fifth of the entire world’s total yearly output.
The stunning figures — calculated by the French economist Gabriel Zucman, director of the International Tax Observatory, a research organization funded by the European Union — reveal more than a surprisingly rapid increase in the concentration of wealth at the tippy top.
They also reflect a series of important global trends: the growing dominance of a few technology companies leading artificial intelligence development; the shrinking slice of the economic pie that goes to workers; and a deepening inequality that will be handed down to the next generation.
These developments are particularly prominent in the United States, where roughly one-third of the world’s nearly 3,000 billionaires reside — and perhaps the first trillionaire, Elon Musk, depending on how the initial public offering of his rocket and satellite company, SpaceX, goes on Friday.
Their rising wealth, a 40 percent increase in just two years, has coincided with significant changes to U.S. tax laws over the last decade that largely benefited the country’s richest families and stockholders and led to an increase in their political influence.
“It is fundamentally corrosive how the largess of billionaires distorts the political process,” said David Autor, an economist at M.I.T. and the faculty co-director of the Stone Center on Inequality and Shaping the Future of Work.
Why have billionaires seen such a rapid rise in their wealth?
One reason for the sudden surge of growth at the peak of the wealth ladder is the boom in artificial intelligence, which has funneled trillions of dollars of capital investment into a small clutch of tech companies. Nvidia, Apple, Microsoft, Alphabet, Meta and Taiwan Semiconductor Manufacturing Corporation, for example, are each worth more than $1 trillion. Their founders and early investors have reaped most of the financial gain.
We can see it happening with SpaceX’s public offering — set to be the biggest in history. The anticipated Day 1 valuation of the company, whose shares are expected to begin trading on Friday, aims for $1.77 trillion. With 42 percent of the stock, Mr. Musk is poised to become an instant trillionaire.
It’s hard to wrap your head around such vast sums. But consider that only 21 countries in the world have economies that are able to produce enough annual output to reach the trillion-dollar mark.
The stock market is where much of the billionaire alchemy happens. Soaring stock profits have been disproportionately captured by the richest sliver. Yes, you may have a stake in stock prices if you have a 401(k) retirement plan. And those nest eggs will help pay for housing, food, car, gas, electric and other bills when you stop working.
But it’s the top 1 percent of Americans who own half of all stock, according to data from the Federal Reserve. The top 0.1 percent of Americans — a group of about 135,000 households — own stocks that total $13.7 trillion. That is nearly double the $7.1 trillion owned by the bottom 90 percent of Americans, a group of about 115 million households.
The tech firms that are playing an outsize part in generating those returns have created jobs — but so far the numbers of employees are relatively small. Billionaires’ returns are based on investments in capital much more than in those companies’ employees.
Inequality is growing.
The rise of billionaires is accelerating at the same time that workers are getting a smaller share of the wealth that national economies are creating.
Financial assets have traditionally brought home bigger returns than a weekly paycheck. But since the early 2000s, the gap between the two has been growing. Economists point to several reasons: the declining power of labor unions’ bargaining power; the spread of automation, artificial intelligence and other technologies that can replace workers; the movement of manufacturing and other jobs to countries like China; and policies that tax wages much more heavily than income from investments.
Another culprit, though, is the rise of what Mr. Autor and other economists have labeled superstar firms — behemoths that dominate sectors.
These businesses have shifted the balance of power in the economy, allowing owners rather than workers to gobble up more financial rewards.
Superstar firms can also function like monopolies to set prices and keep down workers’ wages and benefits or impose uncomfortable working conditions.
Measuring inequality is difficult. There is a lot of debate about the precise size of the gap between those with the most and those with the least, as well as the degree to which labor’s share of the pie has declined. But there is general agreement among economists who study the issue that the wealthiest are pulling away from everyone else at a faster pace than before.
Tax policy plays a role in building billionaires’ wealth.
In the United States, changes in the tax laws over the past 10 years have steered more benefits to the wealthiest sliver of households, reducing the amount of taxes they have to pay.
A drastic reduction in the corporate tax rate has supercharged the wealth of the ultrarich, enabling them to double down on their gains as corporations use the increased profits to buy back their stock.
The reduction in taxes owed by corporations and the wealthy increases the tax burden on workers, who pay both income and payroll taxes — two types of tax that barely scratch billionaire wealth. It also reduces the public revenue available to pay for health, education, defense, infrastructure and other public benefits at a time when governments are in deep debt.
The mind-busting fortunes have stirred some political support for wealth taxes. The idea was embraced at the Global Inequality Conference in Paris last week. Proposals for wealth taxes have been debated most seriously in France, but also in Germany, Britain, Brazil and the United States.
In California, where more than 200 billionaires live, union leaders helped put the 2026 Billionaire Tax Act on the November ballot. It would impose a one-time tax of 5 percent on a billionaire’s net worth.
The measure, constructed with input from Mr. Zucman and Emmanuel Saez, another economist who has been at the forefront of research on global wealth and inequality, was based on calculations that found California billionaires’ wealth exceeds $2 trillion today — an amount that equals half of what all of the California economy produces in a year. From 2023 to 2025, the wealth of the state’s billionaires grew 144 percent.
They point out that the surging financial and political power of a few hundred individuals contributes to a growing inequality that is likely to persist for generations because most of that wealth escapes taxation, creating a self-perpetuating aristocracy.
As Dario Amodei, the billionaire chief executive of Anthropic, the maker of the chatbot Claude, wrote this year: “We are already at historically unprecedented levels of wealth concentration,” adding that “the thing to worry about is a level of wealth concentration that will break society.”
