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

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

This raised concerns for investors about the index's risk exposure. As many large tech companies continued posting record highs, analysts argued that the top-heavy index was becoming less representative of the economy as a whole.

Some argue that the S&P 500 is actually an actively managed index

Some critics of the S&P 500's selection process argue that human involvement makes it an actively managed index. S&P Global maintains that while a human selects the stocks in the index, those decisions are not made with the intent of maximizing performance, but rather, to provide a snapshot of the largest companies across different industries.

The S&P 500, managed by the same company, is another major stock index

Also run by S&P Dow Jones Indices, the S&P 500 tracks 500 large US firms using market-value weighting. Many analysts view it as a more accurate gauge of the American economy.

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 S&P 500 is composed of 500 companies, but has more than 500 total listings

Since some large companies have dual-class stock structures (like Alphabet and Fox Corporation), there are multiple listings on the S&P 500 for the same company. S&P Global has banned and then reversed bans on companies with dual-class structures multiple times since first allowing dual-class stocks in 2014.

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.

AI investment may be the next major economic bubble

A video examines the massive surge in AI spending—forecast to hit $500B by 2026—and how this may be propping up a fragile US economy. Experts warn that if AI investment slows or under-delivers, the consequences could be felt in markets, jobs and growth.

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.

71% of equity investments in Q1 2025 went to AI companies

That's up from just 14% in 2020, according to JPMorgan, which recently conducted an analysis of venture capital investment trends in the US.

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 major AI industry players are creating a web of circular investments

Bloomberg created a network diagram that shows how companies like Nvidia and OpenAI are fueling the AI money machine. The chart shows that many top AI companies provide significant investments to one another.

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%.

Warren Buffett has worried that AI might end up being as consequential as the development of the nuclear bomb

Berkshire Hathaway chairman Warren Buffett is one of the many people who’ve come face-to-face with the downside effects of AI, and in particular, deepfakes. He was recently shown a deepfake of himself in a video, which caused him to worry about how bad actors will take advantage of the technology.

The Dow’s price-weighted formula makes stock price matter more than size

Unlike most indices, which weigh companies by market value, the DJIA is price-weighted—meaning higher-priced stocks have more influence on its movements. As a result, a company’s share price matters more than its overall size.

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.

Palantir's technology is part of a larger shift in modern warfare

As warfare becomes increasingly technical, Palantir executives say artificial intelligence is going to revolutionize how military leaders in war zones make decisions. They argue that this shift towards "algorithmic warfare," or the integration of large technological enhancements like AI, will enable militaries to be more powerful and make fewer mistakes.

How Anthropic's experimental corporate structure incentivizes safe AI development

As Anthropic is a public benefit corporation, its board is tasked with making sure that AI tools are developed to help people and society thrive. Members of its Long Term Benefit Trust hold no equity in the company, but make up a majority of the board and can act to maintain Anthropic's public benefit purpose.

Scientists increasingly can't predict what AI will do

Most AI systems are so-called "black box" models, where we only see inputs and outputs while the inner workings remain obscure. This piece, written prior to the launch of ChatGPT, cautions developers to know why and how a system produces its results, and not to sacrifice explainability for accuracy.

AI superintelligence is a hypothetical system vastly more capable than humans

Researchers describe superintelligence as an artificial intelligence system that exceeds human cognitive ability in every area. It is viewed as the theoretical evolution of artificial general intelligence, in which AI systems learn and have the capability of a typical human.

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.

Fair use may shield AI companies from potential copyright violations

AI models are trained on enormous datasets built from content scraped from websites across the internet. Copyright law includes a four-factor test to determine whether copies of content fall under fair use, but the law's enforcement has been inconsistent.

One private school network prefers AI to teachers

Alpha School, a private school network that uses AI tutors and human "guides" rather than teachers, is expanding across the US. Its founder says that two hours a day with AI-powered software frees students to pursue their passions. Critics, including the Pennsylvania Department of Education, say the methods are untested.

Nvidia's attempted Arm acquisition revealed its hopes of becoming the world's leading AI company

Though Nvidia's acquisition of Arm, another company that designs semiconductors, was ultimately quashed over antitrust concerns, the attempt offered insights into Nvidia's business strategy. Over time, Nvidia has increasingly focused on using its graphics cards to power machine learning, and its platform CUDA is dominant in the sector.

Generative AI is reinventing Internet search

Silicon Valley’s reign over tech, money, and politics

Tesla and X CEO Elon Musk, OpenAI CEO Sam Altman, LinkedIn founder Reid Hoffman, and others are getting into politics. From Musk’s role in President Trump’s second term to Hoffman’s spending on former Vice President Harris’ presidential campaign, more tech CEOs are expanding into politics. This podcast episode by WBUR and American Public Media discusses what the impact could be with so many tech figures engaging in American politics. Listen here.

Explore a list of the world’s weirdest and wildest ETFs

Whether you’re leaping straight into the future and looking for stocks picked by AI, a sci-fi aficionado who wants to invest in space travel, or a drama enthusiast looking to make money on stock market volatility, the ETF market’s weird corners have something for you.

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

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.

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.

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

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.

This site reaches millions of visitors who are tired of AI chatbots and seeking human connection. Pretend to be an AI chatbot and ask questions, provide answers, and draw for people in real time.

A vending machine run with Anthropic's AI went out of business after it was convinced to give away items for free and sell a video game console.

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

Watch how algorithms can be designed to train themselves and self-improve without human input, to the point where the optimized code is too complex for programmers to understand.

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

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

How Amazon operates a 'flywheel' business model, a self-reinforcing cycle that drives continuous growth

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.

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.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

Art theft is the third-largest source of criminal revenues worldwide, thanks in part to the subjective nature of valuing a work of art.

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

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

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

Exploring the Larry Bird punch that almost changed March Madness