In late 2025, the top 10 companies in the S&P 500 made up more than 40% of the index's total value

Why some say the S&P 500 has effectively become an AI fund

The S&P 500 is a market-cap-weighted index, which means companies with larger market capitalizations have a larger impact on the index's overall performance. Many of the top companies in the index are currently tech companies—including Nvidia, Microsoft, Alphabet, and Apple—that all have large investments in artificial intelligence. As a result, some analysts are concerned that the index is overly exposed to risky AI investments.

Before the S&P 500 launched in 1957, Standard and Poor's had a daily index with just 90 companies

Unlike previous indexes from S&P, the S&P 500 could be computed in real time using computer technology that tracked stock tickers across stock exchanges. This innovation is partly what led to 500 companies being listed on the index, a huge increase from the 90 companies in S&P's flagship index when the company had to do all the analysis by hand.

A 'large-cap' company has a market capitalization of more than $10B

The S&P 500 is primarily composed of large-cap companies. The idea is that the index provides a big-picture view of the economy by assessing the performance of many of the largest public companies across different industries. The median market capitalization of companies listed on the S&P 500 is around $40B.

Listen to the methods and strategy of the secretive S&P 500 selection committee

Stocks are added to the S&P 500 by a secret selection committee that meets regularly to assess which companies can remain in the index, which companies need to be added, and which companies no longer meet the criteria. The members of the committee used to be public, but S&P Global decided to keep its members confidential after companies sent packages, letters, and gifts to try to make it into the index.

Investors rely on the S&P 500 as a benchmark for the state of the economy

Since the index represents a broad range of diverse industries, it's become a proxy for the market itself and a common benchmark for investors to compare returns and performance patterns against. Generally speaking, when someone says a stock is under- or out-performing the market, that actually means under- or out-performing the S&P 500. The S&P 500 is exchange-agnostic, and includes companies listed on both the NYSE and Nasdaq.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Critics argue the Dow no longer reflects the modern economy

With only 30 companies and a price-weighted formula, skeptics say the DJIA underrepresents vast sectors of the market. They claim it is outdated, though its close correlation with the broader S&P 500 keeps it relevant.

The Nasdaq's 'Magnificent 7' have an outsized impact on the Nasdaq 100's performance

These seven companies are Alphabet, Amazon, Apple, Meta, Microsoft, Nvidia, and Tesla. They're often responsible for over 40% of the Nasdaq 100 index's gains, but the exact percentage varies from year to year.

The world's 50 most valuable private companies

While public companies typically have the highest valuations, private companies get close. This list breaks down the top 50 as of 2025, with SpaceX at the top with a value of $350B, followed by ByteDance. Over three-fifths of the list are located in the US, with eight in China.

Some institutional investors are growing wary of private equity, as certain investments underperform traditional market indices

Private equity often attracts investors who can afford to tie up capital for long periods of time in exchange for higher returns than traditional investments. For many years, private equity at least tracked with the S&P 500 in terms of returns to investors, but in 2024 and 2025, it underperformed and posted declining returns.

The wealthiest Americans own the vast majority of the stock market

Recent data from the Federal Reserve shows that the richest people in America own 93% of all the country's stock—the highest level ever recorded. Meanwhile, the bottom 50% of Americans held just 1% of all stocks.

Worth more than $14T, Silicon Valley may be getting too expensive for future founders

Silicon Valley, the 1,800-square-mile hub of tech innovation, reached more than $14T in market value in 2024. Home to industry giants like Apple and Adobe, its influence is undeniable. But rising costs and corporate relocations raise questions about its future.

More than 650 companies went public in the US in 1996

As the dot-com bubble reached its peak, most dot-com companies went public with little proof of being profitable and were often overvalued. In 1999, the Nasdaq's price-to-earnings ratio (a tool used to determine a stock's value that divides its price by earnings) hit 90.2, signaling that many companies were operating at a net loss. Startups promised investors that more time and money would help scale their businesses and become profitable.

The S&P 500 has an average intra-year drawdown of -16%

In a given year, the value of the S&P 500 can significantly fluctuate. An intra-year drawdown is the most significant difference between the index's peak and lowest point.

Biotech ETFs allow investors to gain exposure to multiple promising companies in the industry

Biotech ETFs offer a diversified alternative to purchasing an individual biotech stock and gambling on whether an individual company’s clinical trial yields the next blockbuster cancer treatment or an absolute flop. This list of the top biotech ETFs in 2025 can help you learn more about them.

The Vanguard Total Stock Market Index, was worth roughly $1.47T as of February 2024

That fund (and the other seven largest mutual funds by assets) is an index fund, meaning it invests in a specific set of preset securities.

Just because a big name company is going public doesn’t guarantee a successful stock

A reporter dove into how highly anticipated IPOs can still be risky, and why retail investors should be wary of investing right away.

Dozens of S&P 500 stocks, including Coca-Cola and Walmart—known as the dividend aristocrats—have increased dividends every year for 25 years

As of 2021, 8.2% of Fortune 500 CEOs were women

Eighty-five percent of those women were white. A data visualization breaks down what the face of corporate America looks like, plus provides information about the history of female CEOs on the Fortune 500 list.

Many retail investors exited the stock market after 2008, leading to a drop in individual market participation

That changed thanks to GameStop, federal stimulus checks, and strong corporate results in the first quarter of 2021. This chart plots how much retail investors poured into the market each day, reaching records in early 2023.

WeWork’s S-1 was full of alarming financial and business information that concerned investors and the public

When WeWork’s S-1 came out, investors were particularly concerned about WeWork’s expenses far outpacing its growing revenue and its complex company structure, as well as a few potential conflicts of interest within the company.

'Planet Money' debates the financial indicators that defined 2025

In this end-of-year episode, "Planet Money" stages a playful debate over which economic indicators best captured the chaos of 2025—from tariffs to AI bubbles—and which signals may matter most as the US economy heads into 2026.

The K-pop industry's Big Four are facing declining stock prices

The major players of the K-pop industry—SM, JYP, YG, and HYBE—are publicly listed companies. Despite huge financial successes, these corporations have recently dealt with plunging stock prices, losing between 29% and 56% of their market cap by late 2024. While there’s no one reason for the recent devaluation, there are signs of slowing enthusiasm and less action from the major players—BTS and Blackpink.

Warren Buffett has said not investing in Google or Amazon early enough was a mistake on his part

After avoiding investing in tech stocks during the dot-com boom, Buffett's stance on investing in tech was widely criticized. Buffett later shared his thoughts on why he regrets not investing early enough.

Many startups in a variety of industries try to reframe themselves as 'tech companies'

Tech is still the dominant industry for startups—in part due to its low barriers to entry, high growth potential, investor preferences, and the proliferation of tech into a wide variety of industries. Sweetgreen, the fast-casual salad chain, for instance, has often referred to itself as a tech company.

Tesla short sellers benefited from the company's poor performance in 2025

Tesla was widely considered the most-shorted stock until 2024, despite consistent short-seller losses. Between 2016 and 2020, short sellers reportedly lost more than $11B as Tesla's stock price continued climbing. However, long-held short positions began paying out in 2025 as Musk's foray into politics and his eventual feud with President Trump hurt Tesla's stock performance. In 2025, Tesla short sellers made more than $10B.

The financial crisis in 2008 had a major impact on many 401(k) plans

Amid the 2008 financial crisis, stocks and bonds cratered as the broader market floundered due to the subprime mortgage crisis. Investors with so-called "target-date" funds—which shift allocations based on the maturation of a fund—shared in the slump, with some funds declining by 20% or more just a year or two away from maturation.

SpaceX's S-1 or 'prospectus' revealed many previously unknown details about the company, including its unprofitability despite doing $18.7B in revenue in 2025, exactly how many voting shares Elon Musk will have in the company (roughly 85%), and more.

In 2025, four executives from large tech companies were given positions in the US Army Reserves—including Palantir Chief Technology Officer Shyam Sankar, which reinforced Palantir's ties with the US military and its role as a leading defense partner.

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Hedge funds, the private investment firms that trade a wide swath of financial assets, make money by imposing steep fees on investors and from the fund's investment performance.

US housing costs have risen by roughly 175% between 1991 and 2026—but a growing number of Gen Zers are becoming homeowners anyway. In 2025, 4% of homebuyers were Gen Z, up from 3% the year before.

The USPS spent $3.97B in 2024, accounting for .058% of the federal budget.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.

Despite being favored by 87% of Americans, Congress does not have term limits.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

11 people died from firework injuries in the US in 2024.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

Up to a million Girl Scouts sell about 200 million cookie boxes every spring, generating $800 million, largely because refusing a child is frowned upon

See a ranking of the best (and worst) Federal Reserve Chairs since 1914 out of the 16 men and women who have held the office since.

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

20,000 letters to the advice columnist 'Dear Abby' provide insight into prevailing sex, religion, and LGBTQ fears, anxieties, and concerns from the 1950s onward.

Poison ivy will likely become both larger and more resilient due to climate change.

See 33 images that became central to huge scandals, including a young Charles and Camilla, Michael Jackson's baby on a hotel balcony, and Hugh Grant's mugshot.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.