The McKinsey Global Institute (MGI) identified 18 “arenas” in 2024—industries that stand out for their dynamism and future potential in both revenues and profits. They include an “AI foundation” set of industries (semiconductors, cloud services, and AI software and services); digitization (digital advertising, E-commerce, streaming video, cybersecurity, and video games); electrification (EVs, batteries, nuclear fission), hard tech (robotics, space, shared autonomous vehicles, commercial drones, modular construction); and new bio frontiers (drugs for obesity and related conditions and non-medical biotech).  

In research published this spring, MGI tracked the development of those 18 arenas and showed them accelerating sharply. Among them are AI-related industries, digital industries like e-commerce, digital advertising, and video games, and other industries such as obesity drugs, robotics, modular construction, and commercial drones.

Combined, MGI finds that the 18 arenas added $18 trillion in market capitalization from 2022–25 and could generate $29 trillion to $48 trillion in revenues by 2040. The arenas are growing significantly faster than other sectors and deliver higher returns. In short, they are where the economic action is.

Right now, the United States and Greater China are by far the most prominent players in these industries, with 50% of the revenues coming from U.S.-based companies and 30% coming from companies based in Greater China. MGI also identified nine “omniscalers”—companies that play leading roles in three or more arenas. Omniscalers are important because they can deploy their strengths in capital, talent, and capabilities to create economies of scope and scale across multiple arenas. So it is notable that six of the world’s omniscalers are based in the United States, two in China, and one in South Korea.

But there are important dynamics at work outside the omniscalers. Firms headquartered in Greater China are strong in arenas related to electrification, where they have the scale, vertical integration, and manufacturing intensity that the United States does not. Supported by strong foundations in industrial and consumer electronics, Japan and South Korea have increased their share of market cap in robotics, modular construction, and video games. Europe leads in market cap in only one arena, nonmedical biotech, but has specialized strengths in batteries and obesity drugs.

While all 18 arenas are growing, a few are accelerating at something approaching warp speed. An “artificial intelligence (AI) foundation set” of arenas—semiconductors, cloud services, and AI software/services—has dominated growth in the arenas since 2022, adding $500 billion in revenues and $10.8 trillion in market cap.

The numbers are impressive. If anything, though, they understate the importance of the AI foundation arenas. AI can improve performance and lower costs across the board, while enabling new business models and technology resets. For example, AI is enabling content creation, agentic commerce, and blurred boundaries among the digital arenas like e-commerce, digital ads, and streaming. And the combination of AI and batteries is revealing new possibilities in hard tech, including shared autonomous vehicles, robotics, and commercial activities in space.

For business leaders, the key is to understand their company’s position in relation to the arenas. The first question to ask is the simplest: Are we in an arena? If so, speed is of the essence in reallocating resources and in adapting governance to  move with agility.

Companies that are not competing directly in an arena may be more exposed than they realize, through impact across the value chain and opportunities for reconfigured operations. Companies that ignore the new dynamics the arenas are creating will likely be left behind. 

Whether you are in an arena or affected by one, it is critical to invest capital with the arenas in mind, either to defend access to critical inputs such as computing power, energy, and supply chain capacity or to fund entry into new markets. And while the recent growth of the arenas has been striking, many companies have deployed enormous capital — and sustained profitable growth, not just market cap gains, is the true measure of success.

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The 18 arenas are already transforming the world—at the individual, household, company, city, country, and global level. No one can know whether they will all continue to outperform; indeed, completely new ones could emerge. Still, the direction of economic travel is unmistakable. Since 2022, the market cap of the 18 arenas has grown four times as fast as other industries and 10x as fast in revenue growth.

Bolstered by deep capital markets that support the scale-up of existing companies as well as promising new entrants, U.S. companies are well positioned, with the majority of market cap in 14 of the 18 arenas. Of the top seven AI foundation companies, six are American. That vitality has helped boost U.S. growth and productivity above that of many other advanced economies.

That is a promising position, not a guaranteed one. The risks and rewards of leadership in the arenas are substantial—and ever increasing. For companies in the United States, staying ahead in the arenas of competition will require nimble and bold actions.

The opinions expressed in Fortune.com commentary pieces are solely the views of their authors and do not necessarily reflect the opinions and beliefs of Fortune.