Biggest US companies: your guide to the largest American businesses

*This article was last updated on March 21, 2024

What are the biggest US companies by market cap?

As of March 2024, the top 10 largest companies in the US by market cap are as follows:

*According to copmaniesmarketcap.com as of March 21, 2023

The biggest company in the US: Microsoft (NYSE:MSFT)

The biggest company by market cap in the US is Microsoft. The company was founded in 1975 by Bill Gates and Paul Allen. Over the last five decades, it has played a pivotal role in shaping the modern digital landscape. Today Microsoft remains at the forefront of the tech industry with strong investments in the AI space, most notably its multibillion-dollar alliance with OpenAI.

Microsoft first revolutionized personal computing when it launched Microsoft Windows, a user-friendly graphical interface that remains the most popular computer operating system today.

Other popular Microsoft products include the Microsoft Office suite, a toolkit of software systems used for businesses and individuals alike. Microsoft’s web browser, Internet Explorer, was the dominant browser for more than a decade as internet usage and personal computers became ubiquitous. It’s since been replaced with Microsoft Edge.

Presently, Microsoft is focusing its attention on new technologies including artificial intelligence, quantum computing, and more with its cloud computing platform Azure. The company is one of the largest investors in the privately held OpenAI, valued at more than $80 billion.

The rest of the biggest American companies

2. Apple (NASDAQ:AAPL)

Another tech giant, Apple’s main business lines include mobile phones, desktop and personal computers, services, wearables, home technologies and other accessories.

Apple was the first US-based company to reach $1 trillion in market capitalization in 2018. The company has reached more than three times that value in the past, and last year held the title of the most valuable US company before being superseded by Microsoft.

Apple was founded in 1976 by Steve Jobs and Steve Wozniak. Together the Steves created leading personal electronics popular for their sleek design and user-friendly interfaces. It wasn’t until 2007 with the launch of the iPhone that Apple became a household name, popularizing smartphones and music streaming devices across the globe.

However, Apple has recently received pushback in the form of a US antitrust lawsuit for building a smartphone monopoly. The landmark suit filed on Thursday, March 21, is another blow to the company which is already facing numerous antitrust inquiries around the world that threaten its $85 billion services revenue at risk.

Apple has acquired more than 110 companies over the years. Some of them for the technological innovations now used in many Apple products such as FaceID, and others as separate technology products like Beats Electronics audio devices. Read the full list of Apple acquisitions here.

3. NVIDIA (NYSE:NVDA)

NVIDIA is a microprocessor manufacturing company creating graphic cards and other advanced computing hardware. Founded in 1993, NVIDIA has emerged as a key player in the fields of gaming, data centers, artificial intelligence, and autonomous vehicles with the use of its graphic processing units (GPUs).

NVIDIA has made significant strides in the AI and data center domain. Its semiconductors are widely adopted in machine learning and deep learning applications, accelerating complex computations and data processing. This strong foothold in AI has bolstered NVIDIA's presence in data centers and autonomous vehicles, two sectors currently experiencing tremendous growth.

4. Amazon (NYSE:AMZN)

Amazon is an e-commerce company that reshaped the retail landscape with Amazon.com. The company has more recently focused on expanding into cloud computing, smart home devices, and entertainment media with more than 100 acquisitions.

Amazon has been growing its cloud service provisions, mainly Amazon Web Services (AWS) as part of its initiative to invest in new technologies. AWS provides computing power, cloud storage, and databases to online businesses as one of the largest web hosting providers.

5. Alphabet (NYSE:GOOG)

Alphabet, formerly known as Google, is another tech conglomerate at the forefront of the industry. The company’s most popular software includes its search engine, Google; video streaming platform, YouTube; mapping system, Google Maps; plus its email service and suite of office products, Google Suite.

Alphabet also develops Android, a mobile operating software with an open-source project that runs on over 70% of smartphones worldwide. It is the main competitor to Apple’s iPhone.

The pervasiveness of Google’s search engine also drives its powerful digital advertisement service. Because of Google’s web search dominance, Google controls access to more than 85% of the digital ad-serving market according to 6Sense. Advertising is the main revenue-generating segment of the company. In 2022, 80% of Google’s revenue came from advertising through Google’s search engine and on YouTube. 

Trade the biggest companies in the US

With City Index, you can trade all the companies listed here via CFDs – enabling you to go long and short on their price movements. Follow these steps to get started:

1. Open your City Index account and add some funds
2. Log in to our award-winning Web Trader platform, or download our mobile trading app
3. Search for your chosen US company
4. Choose to buy to go long, or sell to go short
5. Monitor and close your position

Alternatively, you can trade US companies – alongside 1,000s of other markets – risk free with a City Index demo account. Your demo comes with £10,000 in virtual funds to trial trading without putting up any capital.

6. Meta Platforms (NYSE:META)

Meta Platforms (formerly Facebook) operates the world’s largest social network connecting billions of users on multiple platforms. Meta’s major products include:

• Facebook
• Instagram
• WhatsApp

Most of Meta’s revenue comes from advertisements on its platforms, mainly Facebook and Instagram. Meta has faced numerous lawsuits presented by federal agencies for antitrust and privacy infringements.

7. Berkshire Hathaway (NYSE:BRK-B)

Berkshire Hathaway is a holding company run by famous investor Warren Buffett. It’s grown from a small textile company acquired by Buffett in the 1960s to one of the largest companies in the world. Berkshire Hathaway owns dozens of private companies including insurance provider GEICO and clothing brand Fruit of the Loom. The conglomerate also owns significant amounts of public companies like Coca-Cola, Apple, General Motors, and American Express.

8. Eli Lilly (NYSE:LLY)

Eli Lilly is an American pharmaceutical company known for its clinical depression drugs Prozac and Cymbalta along with its diabetes drugs Humalog and Trulicity.

Eli Lilly’s stock value as seen strong growth in the past year, with an EPS increase of 58.02% year-over-year and revenue growth of 26.9% to $8.83 billion for the same period as of March 2023.

This growth can be attributed to market share gains for several of its diabetes drugs, including the recently approved Mounjaro and Zepbound. Obesity drugs designed for diabetics like Novo Nordisk’s Ozempic and Wegovy have become wildly popular, and LLY’s newest obesity and diabetic drugs are expected to bring in tens of billions in annual revenue in the coming decade.

9. Broadcom (NASDAQ:AVGO)

Broadcom Inc. designs, manufactures, and supplies semiconductors and related infrastructure software. It’s experienced fantastic growth over the past year, capitalizing from the “AI boom” of 2023. AVGO stock is up 95%, while competing microprocessor developer AMD is up 85%.

In 2023, Broadcom reported revenue of $35.82 billion and a net income of $14.08 billion. It’s 2024 estimates sit at $50 billion in revenue with $10 billion of that figure coming from the sale of AI chips.

10. Visa (NYSE:V)

Visa is a global financial services company that provides infrastructure for banking services in over 200 countries around the world.

The company does not issue cards or extend credit. Instead, it provides financial institutions with banking-related products such as Visa-branded cards and payment processing systems. The company operates four data centers in the US, England, and Singapore that process over 100 billion transactions a year.

The biggest firms in the US by revenue

Market cap isn’t the only measure of a company’s size. Here are the top US companies by revenue in the most recent fiscal year.

*According to companiesmarketcap.com as of March 21, 2024

As you can see, revenue doesn’t always stack up against market cap. While Amazon and Apple are near the top of both lists, there are some notable differences.

Walmart (NYSE:WMT)

Walmart is a multinational retailer that operates a chain of big box stores in several American countries as well as South Africa and India. Not only the largest company in the world by revenue, it also tops the list for largest private employer with over 2 million employees. Walmart is majority-owned by the Walton family, whose living members are descendants of its founding brothers.

As a company, Walmart is already deeply established in the US and its profit margins are low, so there is little reason to expect high growth from the retailer. Coupled with the competition from online retailers like Amazon, Walmart’s valuation of $415 B is actually lower than its revenue.

ExxonMobil (NYSE:XOM)

ExxonMobil is a multinational oil and gas company originally founded as Standard Oil by American entrepreneur John D Rockefeller. The company was renamed in 1999 after it facilitated the merger of Exxon and Mobil.

Headquartered in Houston, Texas, ExxonMobil makes a majority of its revenue from the exploration, extraction and chemical production of oil and natural gas. ExxonMobil is the largest publicly owned energy company and produces 3% of the world’s total oil.

The oil and gas company has a relatively high market cap. It ranks 15 on our list, but it moves significantly higher on the list when ranked by revenue. That’s because oil and gas stocks tend to be quite volatile, so investors may not be as keen to invest in oil companies despite them having higher revenues than other companies on the list.