The SPDR S&P 500 ETF is one of the most highly traded funds on the market

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, 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.

See a timeline of S&P Global's history—the company behind the S&P 500

From the 1941 merger of Standard Statistics and Poor's Publishing to the creation of the S&P 500 in 1957, the company that created the famous index has long been a leader in financial intelligence.

Watch how the S&P 500 is actually calculated

After accounting for each company's float-adjusted market capitalization (a metric that combines the price of a company's stock, the total number of shares, and the stock's float, which means how many shares are actually available), the S&P 500 formula uses a divisor to create the index number. However, what the divisor is and what it represents are secrets.

The S&P 500 selection committee has strict rules around adding a company to the index

While the decision to add a company to the index is ultimately up to the selection committee, any prospective company has to meet some criteria to be considered. To join, the company must have been profitable for the last four quarters, must have a market capitalization exceeding $22.7B, and meet certain requirements around tradeable stock availability (or float).

The S&P 500 yields a roughly 10.5% average annual return

Tthe factors that go into that calculation are multifaceted—from how inflation impacts it to the stocks themselves. During periods of high inflation, stock performance can be stunted by investor concerns, for instance. The average return also varies based on whether dividends are included.

See the top 100 ETFs by trading volume

This list grabs the top 100 by trading volume, or the average number of shares that have traded hands over a 3-month period. Top of the list is a semiconductor-focused fund from Direxion, followed by other tech-centric offerings.

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.

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.

Read how Vanguard's founder used the S&P 500 to revolutionize retail investing

John Bogle, the founder of The Vanguard Group, created a fund that tracked the S&P 500 in 1976. That fund created an unprecedented opportunity for individual retail investors, brought down fees across the board, and popularized the belief that passive, low-cost index fund investments would outperform actively managed portfolios long-term.

Meet the ‘SPY kids’ tied to Wall Street’s first ETF

When SPY became the first ETF to launch in 1993, regulators wanted its issuers to set a termination date. After initially saying the fund would cease to exist in 25 years, its issuers came up with a different strategy. They named 11 children born between 1990 and 1993 and declared that the fund would cease to exist in 2118, or 20 years after the last of the 11 “SPY kids” died. The kicker? According to Bloomberg, none of the children knew they were connected to the fate of this giant fund.

ETFs are rising in popularity

While less than half of retail investors hold ETFs in their portfolio, this figure is up dramatically in recent years, and experts forecast continued adoption as more options hit the market and total ETF assets under management continue to grow.

The total cost of owning an ETF is the sum of the holding costs and the transaction costs

Holding costs include things like the expense ratio, or the annual fee that a fund issuer charges. Transaction costs include things like brokerage commissions, or the fee that a broker charges to enact a trade. However, in recent years, most brokers have essentially eliminated commissions on ETF trading.

The stock market's volatility between 2017 and 2025, visualized

The CBOE Volatility Index measures expected stock market volatility using the prices of options on the S&P 500. When traders expect large moves in the market, options prices tend to rise as more options are purchased to bet on the direction of the move.

Test your ETF knowledge

A 10-question quiz from the SEC allows investors to test their basic knowledge about exchange-traded funds and their investing counterparts, mutual funds. Here’s a sample question: Is the past performance of a fund a good indicator of future results? (Hint, the answer is no).

90 percent of active managers of large public funds underperform

High fees tend to eat away at whatever edge professional managers accrue, resulting in most such funds performing worse than their underlying benchmark indexes like the S&P 500.

Investors collectively own $28T in US Treasury securities

The 10-year Treasury yield is a central measure of the health of the economy, shaping how much both the government pays on its debt and the cost of borrowing for the private sector. This explainer provides stats and explainers on the important metric.

The SEC recently approved bitcoin ETFs in landmark investing decision

In January 2024, the US Securities and Exchange Commission made history when it decided to allow fund issuers to launch bitcoin ETFs. This new class of exchange-traded fund tracks spot bitcoin prices, essentially allowing investors to hold bitcoin without actually having to buy the crypto.

SPACs, explained

Special purpose acquisition companies make it easy for mature unicorns (companies valued at over $1B) to receive growth capital by going public. This process effectively skips the work of a traditional initial public offering, and its time-intensive investor negotiations. Typically, a well-known investor with expertise in a certain industry sponsors a SPAC with the intent to acquire a startup. Learn how it works and the risks involved here.

The fees for keeping a company listed on the NYSE are typically higher than the Nasdaq's

The current maximum annual listing fee for companies listed on the New York Stock Exchange was $500K as of early 2026. The maximum annual listing fee for companies listed in Nasdaq's top tier, on the other hand, was of $193K. Companies listed must pay these fees each year.

The number of publicly traded companies has decreased in recent years

In 1996, more than 7,300 companies traded publicly on US stock markets, but that number has recently dropped to 4,300. Economists point to two reasons: First, going public requires full disclosure of operations, exposing it to scrutiny from investors, competitors, and analysts. Second, the IPO process is expensive and time-consuming.

While day trading has risen in popularity in recent years, the SEC warns it is a speculative strategy that can cause big losses

A day trader is anyone who buys and sells a stock within the same trading day. They quickly move in and out of the market to try and profit. Some day traders are professionals, while others are retail investors.

There are ETFs that track lawmakers' stock purchases

If you can’t get enough politics in your life, why not invest like a politician? Because members of Congress are required to disclose their stock purchases, you can do just that, and the NANC and KRUZ ETFs make it even easier. NANC, referencing Nancy Pelosi, holds a basket of stocks that Democratic politicians have purchased. KRUZ, referencing Ted Cruz, holds a basket of Republican-held stocks.

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

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.

Shares are parts of a stock that represent ownership of a company

Shares are traded on the stock market. Once you buy a single share of a company, you are considered a shareholder of that company and may have certain rights as a partial owner, such as voting on business decisions.

Who are the people standing on the floor of the NYSE?

Today, not all of the trading is done on the floor of the New York Stock Exchange itself (computers help now), so it isn’t as chaotic as it once was. However, the NYSE is one of the few remaining trading floors where much active trading still happens in person.

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.

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Sovereign wealth funds in the Middle East and Asia surged after the 2008 financial crisis

As the stock market plummeted in 2008, SWFs with cash on hand were able to snap up critically undervalued assets that eventually posted large profits. The Government of Singapore Investment Corp. and Abu Dhabi Investment Authority invested $14.4B in Citigroup, resulting in a $1.6B profit for the GSIC when it sold half of the holdings in 2009.

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%.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

44% of Americans say they pray at least once a day—discover how your state's religiosity stacks up against the rest of the country.

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

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.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

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

The 1987 Nintendo video game 'Stadium Events' isn't known for being particularly fun, but its scarcity has made it a highly sought-after item that has sold for up to $35K at auction.

Fireworks-related ER visits are on the rise—in 2024, they increased by 52% as compared to the prior year.

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.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

'Saturday Night Fever,' the 1977 film that introduced disco to the mainstream, was based on a fabricated magazine story.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

Three Ebola species are responsible for most large outbreaks of the disease, yet the only approved Ebola vaccine is known to work against just one of them.