More than 200 investment products with over $800 billion in assets tracked the Nasdaq-100 in mid-2026, by Nasdaq's count, and QQQ is the best known of them. The index is often called the tech index, but its rules are what produce that tilt: who may join, how large one member may grow and how fast a newly listed giant gets in. This guide explains those rules as rewritten in May 2026, measures how concentrated the index was on September 30, 2026 and sets its record beside the S&P 500. For investing basics, start at the stocks hub.
What is the Nasdaq-100?
The Nasdaq-100 is an index of 100 of the largest non-financial companies listed on Nasdaq, weighted by market value with caps on the biggest members.
Nasdaq has calculated it since January 31, 1985, from a base value of 125, under the ticker NDX; a version with dividends reinvested, XNDX, runs from March 1999. Membership is not limited to American companies. Foreign firms whose main listing is on Nasdaq qualify too, and on October 29, 2026 QQQ held three of them through American depositary receipts: ASML, Arm and PDD Holdings. International stocks for US investors explains how those receipts work.
The name invites confusion with the Nasdaq Composite, a far broader measure of Nasdaq-listed stocks that includes financial companies. Dow Jones vs S&P 500 vs Nasdaq compares the two with the Dow and the S&P 500.
The count is rarely exactly 100. Alphabet appears twice, through its class A and class C shares, and a company added under the fast-entry rule described below does not push anyone out, so the index can carry more than 100 companies until the December reset.
Which companies can join the Nasdaq-100?
A company needs its main listing on Nasdaq and a non-financial business, and its shares must pass tests for type, trading and time on the market.
| Test | Rule in the methodology effective May 1, 2026 | What it screens out |
|---|---|---|
| Listing | Primary listing on a US Nasdaq exchange, excluding the Nasdaq Capital Market tier | Companies whose main listing is on the NYSE or abroad |
| Industry | Not in the Financials industry of the Industry Classification Benchmark; real estate companies allowed unless organized as REITs | Banks, insurers, brokers, asset managers and REITs |
| Share type | Common stock, tracking stock or American depositary receipt | SPACs and when-issued shares |
| Trading | Average daily value traded of at least $5 million over three months | Thinly traded shares |
| Seasoning | Three full calendar months of trading on Nasdaq, the NYSE, NYSE American or Cboe BZX, not counting the month of listing | Most new IPOs, unless they qualify for fast entry |
| Float | No minimum | Nothing; shares with a small float get a reduced weight instead |
| Status | Not bankrupt and not committed to a takeover, delisting or liquidation | Companies on their way out |
There is no size floor and no profit test, two hurdles the S&P 500 sets. Rank does the work instead. On the last trading day of November, Nasdaq ranks every eligible company by full market capitalization, which counts unlisted share classes as well as listed ones. The top 75 are in automatically, members ranked 76 to 100 keep their seats, and members ranked 101 to 125 stay if they were in the top 100 a year earlier or joined since. The largest non-members fill any seats left, and the new list takes effect on the first trading day after the third Friday in December.
That 101-to-125 band works as a buffer, so a member that slips a few places is not dropped one year and re-added the next, forcing funds to sell and then rebuy the same shares. In March, June and September, Nasdaq updates share counts and removes any member ranked outside the top 125, bringing in the largest eligible outsider if the count would otherwise drop below 100. It also adds any non-member that ranks among the 40 biggest companies in the index.
Two changes in 2026 show the routes in. Walmart moved its listing from the NYSE to Nasdaq on December 9, 2025, and replaced AstraZeneca in the index on January 20, 2026. SpaceX went public on Nasdaq on June 12, 2026, and joined on July 7 under the new fast-entry rule, with no member removed to make room.
What changed in the Nasdaq-100 rules in 2026?
Nasdaq rewrote several rules effective May 1, 2026, after a February consultation, mainly to admit very large new listings quickly without forcing funds to chase scarce shares.
- Fast entry. A new listing whose full market value would rank among the 40 largest members is measured on its seventh trading day, announced after its tenth and added after its fifteenth, skipping the three-month wait. Nasdaq's FAQ said that, as of March 2026, only companies worth more than about $100 billion would have qualified. An existing listing that climbs into the top 40 is added at the next quarterly review.
- A float cap instead of a float minimum. The rule barring companies with less than 10% of their shares freely tradable is gone. Weight is now calculated on the lesser of a company's listed shares or three times its free-floating shares, and floats are re-measured every quarter.
- Ranking on all shares. Companies are ranked on listed and unlisted shares combined, though only listed shares count toward weight.
- A top-125 test. A member is removed at a quarterly review if it ranks outside the top 125. The old rule dropped members that weighed under 0.10% of the index for two straight month-ends and ranked outside the top 100.
- A wider listing rule. A primary listing on any US Nasdaq exchange now qualifies; the old wording required the US listing to be exclusively on the Global Select or Global Market tiers.
An earlier round, effective June 24, 2024, replaced a minimum trading volume of 200,000 shares a day with the $5 million daily value test, added the 10% float minimum that 2026 then removed and dropped a requirement that foreign issuers have US-listed options.
Worked example: How the three-times-float cap sets a new member's weight
Suppose a company lists on Nasdaq with a full market value of $1.5 trillion but only 5% of its shares freely tradable, worth $75 billion. Assume all its shares are listed.
- Weighting value: the lesser of $1.5 trillion or 3 × $75 billion, which is $225 billion
- The index therefore weights it like a $225 billion company, 15% of its real size
- If its float later reaches 15%, three times float is $675 billion, and its weight rises at the next quarterly review
- Once the float reaches one-third, three times float covers every share and the cap stops binding
SpaceX shows the cap at work. CNBC reported that it was expected to enter at a weight under 1% despite its size, and on October 29, 2026 it made up 2.67% of QQQ, the fund's ninth-largest holding.
How does the Nasdaq-100 cap its largest companies?
Weights follow market value until one of two limits is hit: no company above 24%, and no more than 48% in companies weighing over 4.5%.
Nasdaq checks both at each quarterly rebalance and watches daily closing weights in between. If a company is above 24%, every company is cut to 20% or less. If the group above 4.5% reaches 48%, that group is scaled down to 40% and the freed weight is spread across the other members, keeping everyone in their original size order. At the December reset, two further limits apply to individual share lines: none above 14% if any passes 15%, and the five largest cut to 38.5% combined if they reach 40%, with every other line held to 4.4% or the fifth-largest weight, whichever is lower.
The thresholds sit just inside the diversification tests that the federal tax code sets for regulated investment companies such as QQQ. Those tests cap any one issuer at 25% of a fund's assets and require at least half its assets to be in cash, government securities or positions of no more than 5% each.
Worked example: Checking QQQ's September 2026 weights against the caps
- Largest company: Nvidia at 8.33%, far below the 24% trigger
- Companies above 4.5%: Nvidia 8.33%, Apple 7.35%, Alphabet 5.90% across its two share classes, Microsoft 5.76% and Micron 5.02%, a total of 32.36%
- Room before the 48% trigger: 48% − 32.36% = 15.64 percentage points
- Five largest share lines for the December test: Nvidia, Apple, Microsoft, Micron and AMD at 4.17%, together 30.63%, under the 40% trigger
QQQ's weights track the index closely, though they are not identical to it.
The rule last bit in 2023. On July 7, Nasdaq announced a special rebalance because members above 4.5% had pushed past the 48% limit; Microsoft alone weighed 12.91%, Nvidia 7.04% and Amazon 6.89%, according to Nasdaq Dorsey Wright. Using prices from July 3, the group was cut to 40% before the open on July 24, 2023, with no member added or removed. Dorsey Wright counted it as the third special rebalance in the index's history and the first since 2011. For a QQQ holder it was a trade rather than a loss: the fund sold part of its largest positions and bought more of everything else.
How concentrated is the Nasdaq-100 compared with the S&P 500?
Considerably more: on September 30, 2026, the ten largest holdings made up 46.68% of QQQ, against 39.1% for the ten largest in the S&P 500.
| Holding | Weight in QQQ | ICB industry, used by Nasdaq | GICS sector, used by S&P |
|---|---|---|---|
| Nvidia | 8.33% | Technology | Information technology |
| Apple | 7.35% | Technology | Information technology |
| Microsoft | 5.76% | Technology | Information technology |
| Micron Technology | 5.02% | Technology | Information technology |
| Advanced Micro Devices | 4.17% | Technology | Information technology |
| Amazon | 4.07% | Consumer discretionary | Consumer discretionary |
| Meta Platforms | 3.26% | Technology | Communication services |
| Alphabet class A | 3.05% | Technology | Communication services |
| Alphabet class C | 2.85% | Technology | Communication services |
| Tesla | 2.82% | Consumer discretionary | Consumer discretionary |
| Top ten | 46.68% |
By industry, Invesco put technology at 68.0% of QQQ, consumer discretionary at 15.1%, telecommunications at 5.9%, health care at 3.8% and industrials at 2.8%, with consumer staples, basic materials, utilities and energy sharing the last 4.3%. Financials, by rule, had nothing.
Part of the gap with the S&P 500's 39.71% in information technology comes from labels. Nasdaq uses FTSE Russell's Industry Classification Benchmark, which files Alphabet and Meta under technology as consumer digital services, while the GICS system behind the S&P 500 puts them in communication services. The tilt is still real: on the same date the S&P 500 held 11.40% in financials and 9.26% in health care.
Most of the weight overlaps. Every company in QQQ's top ten is also an S&P 500 member, so owning both kinds of fund buys the same giants twice. The differences sit further down: foreign companies such as ASML and Arm, which the S&P 500's requirement for US-based companies keeps out, and SpaceX, which S&P's 12-month waiting period for new listings, kept after a June 2026 review, bars until mid-2027. Growth vs value investing covers the investing style this mix tends to represent.
How has the Nasdaq-100 performed against the S&P 500?
Better over most recent periods: in the ten years to September 30, 2026, it returned 21.16% a year with dividends reinvested, against 15.33% for the S&P 500.
| Period to September 30, 2026 | Nasdaq-100 | S&P 500 | QQQ at net asset value |
|---|---|---|---|
| 1 year | 24.00% | 15.74% | 23.74% |
| 3 years, per year | 28.31% | 22.89% | 28.05% |
| 5 years, per year | 16.56% | 13.79% | 16.33% |
| 10 years, per year | 21.16% | 15.33% | 20.91% |
| Since March 10, 1999, per year | 11.11% | 8.62% | 10.88% |
All figures are total returns from Invesco's QQQ fact sheet. March 10, 1999 is the day QQQ began trading.
Worked example: What the return gap meant for $10,000
- Ten years in the Nasdaq-100: $10,000 × 1.2116 to the 10th power, about $68,170
- Ten years in the S&P 500 at 15.33% a year: about $41,632, so the Nasdaq-100 ended roughly $26,500 ahead
- Ten years in QQQ itself at 20.91%: about $66,776, some $1,394 behind its index after fees and trading costs
- From March 10, 1999, about 27.6 years: about $182,400 in the Nasdaq-100 against about $97,600 in the S&P 500
The long-run figure includes the 2000–2002 crash, and the Nasdaq-100 still came out ahead. Even measured from each index's March 2000 peak to September 30, 2026, on price alone, it grew 7.29% a year to the S&P 500's 6.26%, based on daily closing levels. The lead came with wider swings, though. Invesco's figures show total returns of −32.38% in 2022 and 55.13% in 2023; the S&P 500 lost 18.04% in 2022, according to NYU Stern data.
How do you invest in the Nasdaq-100?
An index cannot be bought directly, so investors use funds that hold its members at index weights, and the best known is Invesco QQQ.
QQQ began trading on March 10, 1999. It converted from a unit investment trust into an open-end ETF in December 2025 and now charges an expense ratio of 0.18%, or $18 a year on $10,000. Other ETFs and index mutual funds follow the same index at different costs. What is an ETF explains the structure, and index funds explained shows how to compare fees and tracking.
The latest QQQ price is $690.56 (Nov 2, 2026), and the QQQ page charts its history. The table below sets QQQ beside SPY, an S&P 500 fund, on price returns over one to ten years, the deepest fall from a peak and how widely each price moved over the past year. Dividends are left out.
| Asset | Last close | 1 year | 3 years (per year) | 5 years (per year) | 10 years (per year) | Worst drop from a high | Volatility (1 year) |
|---|---|---|---|---|---|---|---|
| Invesco QQQ (Nasdaq 100) | $690.49 | +10.3% | +25.5% | +12.3% | +19.4% | -53.5% (Nov 20, 2008) | 20.3% |
| SPDR S&P 500 ETF | $755.72 | +11.2% | +22.1% | +10.5% | +13.5% | -56.5% (Mar 9, 2009) | 12.8% |
Anyone who already owns an S&P 500 fund should count what a Nasdaq-100 fund adds: mostly a larger stake in the same top companies. For a lump of cash, lump sum vs dollar cost averaging backtests both approaches on QQQ.
What are the risks of investing in the Nasdaq-100?
The main risks come from its design: a narrow index built around a few large technology companies can fall much further than the broad market.
Worked example: Buying at the March 2000 peak
- Close on March 27, 2000: 4,704.73
- Close on October 7, 2002: 804.64, so $10,000 had shrunk to about $1,710, a loss of 82.9%
- Gain needed to get back to even: 4,704.73 ÷ 804.64 − 1, about 485%
- First close above the old peak: November 3, 2015, more than 15½ years after the top
- These are price figures; reinvested dividends would have shortened the wait a little
The S&P 500 fell 49.1% over nearly the same stretch, from March 24, 2000 to October 9, 2002, and was back at its peak on May 30, 2007, according to Yardeni Research. Bear markets and corrections lists every S&P 500 decline since 1946.
- Repeat declines. The Nasdaq-100 fell 35.6% from its close on November 19, 2021 to December 28, 2022, against 25.4% for the S&P 500 in its 2022 bear market, and took until December 15, 2023 to recover.
- Concentration. On September 30, 2026, three chipmakers, Nvidia, Micron and AMD, made up 17.52% of QQQ, and five companies more than 32%. A slump in one industry would hit the index hard.
- Missing sectors. With no banks or insurers and little in energy, utilities or consumer staples, the index is a slice of the market, not a substitute for a broad fund.
- Changing rules. Nasdaq rewrote eligibility in 2024 and again in 2026. Fast entry means tracking funds now buy giant IPOs within about a month of listing, at prices formed over a short trading history.
- No guarantee. A ten-year lead over the S&P 500 says nothing about the next ten years, and the investor who bought at the 2000 peak needed more than 15 years just to break even.