What Are the S&P 500 Inclusion Criteria?

To be added to the S&P 500, a company has to clear a set of hard numerical thresholds and then win approval from a committee. The S&P 500 inclusion criteria require, at a minimum, a total market capitalization of $22.7 billion, four straight quarters of positive GAAP earnings, a U.S. domicile, listing on an eligible U.S. exchange, and enough public float and trading volume to absorb the demand that index funds will create. Meeting every criterion makes a company eligible. It does not guarantee a seat.

Market Capitalization Minimum

The current floor is $22.7 billion in total company-level market capitalization, a threshold S&P Dow Jones Indices updated in July 2025.¹ S&P revisits the number periodically so the index keeps tracking the large-cap segment of the market as overall valuations move.

Clearing the company-level number is not the whole size test. The stock’s float-adjusted market capitalization, measured at the individual security level, must also reach at least 50% of that company-level minimum. In practice, the publicly tradable shares need a market value of roughly $11.35 billion or more.¹

Public Float and Liquidity

Because the S&P 500 is float-weighted, companies with concentrated ownership can be excluded even when they are huge. The Investable Weight Factor must be at least 0.1, meaning at least 10% of shares have to be available to the general public. Shares locked up by insiders, controlling shareholders, or other strategic holders do not count.²

Two trading tests follow. The ratio of annual dollar value traded to float-adjusted market capitalization must be at least 0.75. That is a turnover gauge: a stock with a $15 billion float that saw only $5 billion of volume over a year (a ratio of 0.33) would fail. The stock must also have traded at least 250,000 shares in each of the six months before the evaluation date.²

The reasoning is practical. When trillions of dollars in passive funds have to buy or sell shares during a rebalancing, the stock needs to be liquid enough to absorb the flow without distorting the price.

U.S. Domicile and Exchange Listing

Only U.S.-domiciled companies qualify. S&P applies a multi-factor test rather than looking at place of incorporation alone. The U.S. portion of fixed assets and revenues must represent a plurality of the company’s total, though it does not need to clear 50%. When fixed assets and revenues point to different countries, fixed assets take priority.³

If the asset-and-revenue test is inconclusive, S&P may still treat the company as U.S.-domiciled when its primary listing, headquarters, and place of incorporation are all in the United States. The geographic breakdown comes from the company’s own annual filings.³

The stock must be listed on an eligible U.S. exchange. The list is broader than many investors assume: the New York Stock Exchange, Nasdaq, NYSE Arca, NYSE American, Cboe BZX, Cboe BYX, Cboe EDGA, Cboe EDGX, the Nasdaq Global Select Market, and the Nasdaq Global Market.²

One timing requirement catches some newly public companies off guard. The stock must have been trading on an eligible exchange for at least 12 months before the committee will consider it. For companies that went public through a SPAC merger, S&P treats the de-SPAC transaction as the equivalent of an IPO, so the 12-month clock starts from the date the SPAC deal closed, not from when the blank-check company first listed.²

The Earnings Test

Profitability is the hurdle that keeps high-growth, high-loss companies out, no matter how large they get. The rule has two parts, and the company must pass both. GAAP net income from continuing operations has to be positive in the most recent fiscal quarter. GAAP net income from continuing operations summed across the four most recent consecutive quarters also has to be positive.²

The “continuing operations” language matters. One-time gains from selling a division and unusual charges from discontinued segments are stripped out. The committee wants to see that the ongoing business makes money under standard accounting rules, not that the company engineered a profitable quarter through an asset sale.

This is one of the biggest practical barriers to inclusion. A company can clear the market-cap and liquidity bars easily while still failing here, and many large tech and biotech firms have waited years for inclusion specifically because they could not string together the required quarters of positive earnings.

Eligible Security Types

Common stock is the default. The index also accepts real estate investment trusts, with the exception of mortgage REITs, and business development companies. Ineligible security types include closed-end funds, exchange-traded funds, American depositary receipts, limited partnerships, and SPACs. A SPAC itself can never join. The operating company that emerges from a de-SPAC merger can be considered once it has 12 months of post-merger trading history.²

Companies with multiple share classes are eligible. S&P Dow Jones Indices reversed its earlier ban on dual-class structures in April 2023 following a public consultation, so firms with multi-class voting arrangements can now be added as long as they meet every other criterion.

The Index Committee’s Judgment

Passing every quantitative test earns a company a place on the eligibility list, not a seat in the index. The final decision rests with the S&P Dow Jones Indices Index Committee, a small group of analysts and economists who exercise real discretion. That makes the S&P 500 a semi-rules-based index rather than a mechanical one.²

The committee’s most visible concern is sector balance. It compares each sector’s weight in the S&P 500 against that sector’s weight in the broader S&P Total Market Index. When technology is overrepresented relative to the full market, the committee may pass over an otherwise-qualified tech candidate in favor of one from an underweight sector such as energy or materials.

Beyond sector composition, the committee weighs whether a company looks like a durable, long-term constituent. A stock that rocketed past the market-cap minimum on a speculative run may get a longer look before being added. There is no automatic queue. Meeting the criteria does not entitle a company to the next open slot.

When Additions Happen

The index is fixed at exactly 500 constituent companies, so every addition requires either a removal or an open vacancy. Vacancies most commonly come from mergers, acquisitions, or spin-offs that force an existing member off the index. The committee also makes changes during quarterly rebalancings on the third Friday of March, June, September, and December.²

Changes are typically announced about five business days before they take effect, giving index fund managers time to adjust. The committee meets monthly and can announce changes outside its regular cycle when corporate events, such as a sudden merger closing, force faster action.

Staying In Is Easier Than Getting In

The bar to remain a constituent is deliberately lower than the bar to join. S&P’s own guidelines state that the market-capitalization criteria apply to additions, not to continued membership. A current member whose market cap slips below $22.7 billion is not automatically removed; it stays unless “ongoing conditions warrant an index change.”¹

The buffer is intentional. Without it, a stock hovering near the threshold would bounce in and out, forcing index funds into pointless and expensive round-trip trades. The committee waits for a significant and sustained decline before acting.

The most common reason for removal is a corporate transaction rather than weak performance. When a company is acquired and its shares stop trading, it comes out of the index and a replacement is picked. Other triggers include a shift in domicile outside the United States, persistent negative earnings, and bankruptcy. Each time, the committee pulls a replacement from the pool of eligible companies to keep the count at 500.²

1
S&P Dow Jones Indices. S&P Dow Jones Indices Announces Update to S&P Composite 1500 Market Cap Guidelines
2
S&P Global. S&P U.S. Indices Methodology
3
S&P Global. S&P Dow Jones Indices Clarifies Domicile Language for U.S. Indices