# Why an ETF's price, NAV and holdings differ between sources

Three numbers on three clocks. NAV once a day, a price all day, holdings daily from the issuer or quarterly from the SEC — and why two holdings files disagree.

*https://stockmarketstack.com/guides/etf-price-nav-and-holdings-disclosure · background to ETF Research & Screeners*

**Answer:** Because each number is taken at a different moment by a different party. NAV is computed once a day, normally at the 4 p.m. close; the market price is whatever the last trade or quote was; an intraday estimate, where one exists, uses prices that may be stale. Holdings are published daily by most US ETFs under SEC Rule 6c-11, but the SEC's own copy is quarterly and up to 60 days late, and vendors repackage either.

## How it works

An ETF has two markets and one portfolio. On the exchange, anybody buys and sells shares from
anybody else at whatever price they agree. Off the exchange, a small set of firms deal with the
fund itself. Rule 6c-11, the SEC rule most US ETFs operate under, calls them authorised
participants: members of a registered clearing agency with a written agreement allowing them to
place orders for **creation units**, blocks of ETF shares the fund issues or redeems in exchange
for a **basket** of securities plus a cash balancing amount.

That second market is what ties the price to the portfolio. The SEC's 2019 adopting release
describes it: if shares trade below NAV, an authorised participant can buy them on the exchange,
assemble a creation unit and redeem it for the more valuable basket; at a premium the trade runs the
other way. Buying the cheap side and selling the dear one pushes the two together. It is an
incentive, not a guarantee — which is why the price and NAV are two numbers, and why the rule makes
the fund publish how far apart they were.

Three figures come out of this, each with its own clock:

- **NAV per share** — in iShares' words, "the price per share at which each fund issues and
  redeems shares", calculated by the fund accountants at the close of regular trading, normally 4
  p.m. Eastern, every day the New York Stock Exchange is open. Once a day, and only then.
- **Market price** — set continuously on the exchange. For disclosure Rule 6c-11 defines it as the
  official closing price, or, where it more accurately reflects value at the moment NAV is struck,
  the midpoint of the national best bid and offer at that time.
- **An intraday value estimate** — iNAV, IIV or IOPV, depending on who is publishing it. Not
  required by the rule, and not computed by the same people as the NAV.

## Three numbers, read on one page

The iShares Core S&P 500 ETF's own page, read on 8 October 2026, showed a NAV of $780.82 and a
closing price of $780.58, both as of 7 October, and a premium/discount of −0.03%. That is the
gap between those two numbers as a percentage of NAV — the definition Rule 6c-11 uses.

The same page explains why even that small gap exists. NAV is struck at 4 p.m.; the closing price is
the last trade, and iShares notes that "the date/time of the last trade sometimes may occur before
4:00 p.m. eastern time", so "ongoing price discovery may result in a deviation" between the two.
Its premium/discount chart describes market price differently again — "the midpoint between the
highest bid and the lowest offer on the listing exchange, as of the time that the Fund's NAV is
calculated". Both are permitted by the rule. A third-party site that shows a premium for the same
fund may be using either, or the last trade it happened to receive, and will rarely say which.

The same page carried four as-of dates: NAV, price and number of holdings as of 7 October, sector
weights and P/E as of 6 October, and the 30-day SEC yield and 12-month trailing yield as of 31
August. Every figure on an ETF page has a date, and they are not the same date.

## iNAV: an estimate the SEC chose not to require

Before Rule 6c-11, ETFs ran on individual exemptive orders, and those orders required an intraday
indicative value. The 2019 adopting release records that exchange listing standards then required
it at least every 15 seconds during regular trading, and that it also goes by iNAV and PIV.

The Commission did not carry the requirement into the rule, and its reasons are the reasons an iNAV
on a quote screen can mislead:

- It "can be stale or inaccurate for ETFs with foreign securities or less liquid debt instruments",
  because it is built from last available quotations while NAV uses fair value when quotations are
  not readily available.
- For funds holding fast-moving securities, dissemination lags mean it can trail the market instead.
- "Because there are no uniform methodology requirements, the IIV also can be calculated in
  different and potentially inconsistent ways."
- Market makers and authorised participants, the release says, no longer use it to evaluate
  arbitrage for fully transparent ETFs. They compute their own intraday values from the published
  daily holdings and use the IIV as a secondary or tertiary check.

So an iNAV is one party's estimate, on one methodology, at one refresh rate. When a site shows an
ETF trading at a "premium to iNAV" during the day, the premium may be in the estimate.

## Premiums and discounts that are not mispricing

Some gaps are structural. The adopting release says an ETF investing in foreign securities "may be
more likely to experience a persistent deviation between market price and NAV per share given that
many foreign markets are closed during the U.S. trading day", and more so when that market is closed
for an extended period. A fund holding Japanese or European shares trades in New York while its
holdings' last prices are hours old; the ETF's price is the market's live estimate, and the NAV is
computed from those older prices or a fair-value adjustment to them. Bond ETFs have a version of the
same problem, because many bonds do not trade every day.

Rule 6c-11 makes the fund disclose the history rather than explain it away. Each business day the
website must show NAV, market price and premium or discount as of the prior business day; a table
and line graph of premiums and discounts over the last calendar year and the quarters since; and the
median bid-ask spread over the last 30 calendar days, computed from the national best bid and offer
every ten seconds. If the premium or discount exceeds 2% for more than seven consecutive trading
days, the fund must say so and discuss the factors believed to have caused it, and leave that
statement up for at least a year.

That page on the issuer's site is the primary record. Any other source is a copy of it or its own
calculation.

## When holdings are published, and by whom

There are two publication regimes, and they are years apart in speed.

**The issuer, every business day.** Rule 6c-11 requires an ETF relying on it to disclose on its
website, before the opening of regular trading, each holding that will form the basis of that day's
NAV calculation — ticker, CUSIP or other identifier, description, quantity and percentage weight —
and those holdings must be the portfolio as of the close of the prior business day. This is a
condition of the rule, not a courtesy — and only for ETFs that rely on it, which not every ETF does
(see below). What is voluntary, according to the SEC's 2026 proposal, is
the monthly holdings some registered funds post on their websites or sell through aggregators on a
lag of 15, 30, 45 or more days.

**The SEC, from Form N-PORT.** Registered funds, including ETFs, report holdings to the SEC on Form
N-PORT. Under the requirements in force on 8 October 2026, monthly reports are filed within 60 days
of the end of each fiscal quarter, and only the report for the quarter's third month is made public,
upon filing. A fund may also report up to 5% of its investments as "miscellaneous securities",
which can stay nonpublic for up to a year.

That second regime is being rewritten, and has not settled:

1. **August 2024.** The SEC adopted amendments requiring each monthly report within 30 days of month
   end and making every month public 60 days after month end (Release No. IC-35308, 28 August
   2024).
2. **April 2025.** It delayed them to 17 November 2027 for fund groups with $1 billion or more in
   net assets, and 18 May 2028 for smaller groups (Release No. IC-35538, 16 April 2025).
3. **February 2026.** On 18 February 2026 it proposed going back: 45 days to file each monthly
   report, and publication restored to the third month of each fiscal quarter, 60 days after
   quarter end (Release No. IC-35962, published 23 February 2026). The stated reason includes
   reducing the risk of outsiders inferring a fund's trading intentions from its reports.
4. **8 October 2026.** The SEC's rulemaking page for the proposal lists the proposal, its Federal
   Register publication and a comment deadline of 24 April 2026, and no final rule.

For daily-disclosing ETFs none of this changes what you can see: the proposal states that its
discussion of publication frequency does not relate to ETFs required to disclose holdings daily
under Rule 6c-11, because N-PORT changes do not affect how often those funds' holdings are made
public. It matters for mutual funds, for ETFs outside the rule, and for anybody whose holdings data
comes from EDGAR. [How to get ETF holdings as data](https://stockmarketstack.com/how-to/get-etf-holdings-as-data) covers
pulling both files and what each leaves out.

## ETFs outside the daily rule

Rule 6c-11 has a boundary. The adopting release lists the ETFs it did not cover as adopted (p. 17 of
the SEC's copy): those organised as unit investment trusts, leveraged and inverse ETFs, ETFs
structured as a share class of a fund with other classes, and actively managed ETFs that do not
provide daily portfolio transparency — non-transparent ETFs, which "would not meet the conditions of
rule 6c-11" and continue under their own exemptive orders. On share classes it is explicit (p. 122):
absent separate relief, such an ETF "cannot operate in reliance on rule 6c-11." The current rule
text separately addresses leveraged and inverse ETFs, which must also comply with Rule 18f-4.

Outside the rule means not required to publish daily, which is not the same as not publishing. Two
S&P 500 funds, read on 8 October 2026:

- **SPY** is a unit investment trust, as State Street's own page says. That page showed fund top
  holdings as of 7 October and offered a full holdings download marked "Daily".
- **VOO** is, in Vanguard's words, "an exchange-traded share class of Vanguard 500 Index Fund". Its
  page showed holdings as of 31 August 2026 — with earlier month ends to choose from — beside a
  closing price and NAV as of 7 October. Vanguard's disclosure policy promises a daily list only
  for "certain actively managed Vanguard ETFs and certain Vanguard index ETFs", and says the
  holdings it shows are "provided on a delayed basis".

So the date beside the holdings tells you which regime you are looking at, and for a fund outside
the rule the issuer, not the SEC, decides how old it is.

European UCITS ETFs sit outside Rule 6c-11 altogether, and their rule is a policy rather than a
frequency. ESMA's guidelines on ETFs and other UCITS issues (paragraph 17) require a UCITS ETF to
disclose in its prospectus, key investor information and marketing material "the policy regarding
portfolio transparency and where information on the portfolio may be obtained". The Central Bank
of Ireland, which authorises most of them, spells out the two permitted policies in its UCITS Q&A
(ID 1012, 42nd edition, 17 April 2025): daily disclosure, made available on a non-discriminatory
basis, or periodic disclosure, under which "appropriate information" goes daily to authorised
participants and market makers to keep the arbitrage working, investors have a documented way to
request portfolio information, and the holdings as at the end of each calendar quarter are
published within 30 business days of the quarter end. Which policy a fund runs is in its
prospectus, and a research site can be slower than either: in the section below, justETF updates
the iShares MSCI World composition once a month. A holdings file for a periodic-disclosure fund is
a quarter-end list however fresh the page that shows it.

For non-transparent ETFs the arbitrage problem is solved another way. For one model, Managed
Portfolio Shares, an NYSE Arca filing quotes the Commission: the portfolio holdings "are not
publicly disclosed on a daily basis"; a verified intraday indicative value, or VIIV, is disseminated
"in one second intervals during Regular Trading Hours"; and like other registered funds each series
must disclose its holdings "on a quarterly basis, within at least 60 days following the end of every
fiscal quarter". The SEC's 2026 proposal describes these funds as "a small number".

If a research site shows a non-transparent ETF's holdings, they are a quarter-end portfolio up to two
months old, whatever date the page is dated.

## Why two holdings files for one ETF disagree

Assume both files are honest. They still differ, for four reasons, in the order worth checking.

**The as-of date.** An issuer file published before today's open is yesterday's close. A
vendor's file may be a month end or a quarter end, and an N-PORT report is the last day of a fiscal
quarter that belongs to the fund rather than the calendar. Compare the dates before you compare a
single weight.

**Cash, futures and the lines that are not stocks.** An index fund equitises cash with futures:
the iShares S&P 500 page says exchange-traded index futures "may be used to offset cash and
receivables for the purpose of tracking the benchmark index". Whether a source shows that contract,
nets it into cash, or drops it changes every weight beside it. Swap-based, leveraged and options
funds are worse: a contract's market value and the exposure it creates are different numbers, and
sources choose differently between them.

**Share count versus weight.** Rule 6c-11 makes the issuer publish both quantity and weight, and only
the quantity is an observation. A weight is a quantity multiplied by a price, divided by a total, and
the price is a choice. The iShares holdings disclaimer is explicit: market value, weight and notional
value are "based off of a price provided by a third-party pricing vendor" that is "not necessarily
the price at which the Fund values the portfolio holding for the purposes of determining its net
asset value"; the holdings shown reflect the investment book of record, which "may differ from the
accounting book of record"; and for non-US holdings the exchange rate for the vendor price is
generally taken at 4 p.m. London, while the valuation price uses the New York close. One issuer, two
sets of prices, two exchange-rate fixings, on the same day.

**Fund versus share class.** A ticker is a share class, and holdings belong to the fund. Where an ETF
is one class of a fund that also has mutual-fund classes, the regulatory holdings are the whole
fund's. The how-to linked above has the case in detail.

**Which file each research site reads.** For SPY on 8 October 2026, with the issuer's fund holdings
dated 7 October: [ETF.com](https://stockmarketstack.com/tools/etf-com) credits FactSet as the data provider on each section of its
page. [Trackinsight](https://stockmarketstack.com/tools/trackinsight) dated its holdings "08/31/26", 500 positions, beside a price
as of 5 October. [ETF Research Center](https://stockmarketstack.com/tools/etf-research-center) printed no as-of date on its top
holdings and counted 494 holdings, against 503 constituents in the index on the issuer's page as of 6
October. [ETF Insider](https://stockmarketstack.com/tools/etf-insider) says most of its data comes from SEC EDGAR and that its
holdings update with the filings, which "are made every quarter". [justETF](https://stockmarketstack.com/tools/justetf), for
the iShares Core MSCI World UCITS ETF, dated its holdings 31 August 2026; it says composition is
"updated once a month", shows it only for ETFs that physically track their index, and names
Trackinsight, FactSet and Xignite among its data providers.

## What you can do about it

**Name the clock before you name the number.** For any price, NAV, premium or weight, find the
as-of date and time next to it. If a source prints none, it is not a source for a decision that
depends on the difference.

**Use the issuer's page as the reference for a Rule 6c-11 ETF.** It is required to publish the prior
day's holdings before the open, plus NAV, market price, premium or discount, the median spread and
the premium history. Every third-party figure for that fund is a copy of that page or a computation
from it, older or not. For a unit investment trust or a share-class ETF, the issuer's page is still
the reference, but read the date beside its holdings first: it may be a month end.

**Read a premium on an international or bond ETF as a timing gap first.** Check the fund's premium
history table on its own site: a fund that sits at a premium every day the underlying market is
closed is showing you its structure, not a bargain or a warning. The 2% for seven days disclosure is
where the rule starts asking for an explanation.

**Treat an iNAV as one estimate among several.** Ask whoever publishes it what it is built from —
the creation basket or the index, and how often it refreshes. The SEC's own position is that it can
be stale and that there is no uniform method.

**Before comparing two holdings files, align four things.** The as-of date; whether cash and
derivatives are lines, netted or dropped; whether you are comparing share counts or weights, and if
weights, at whose prices; and whether the figure is the fund's or a share class's. Compare share
counts on the same date first. If those match, the weights differ only because of price.

**For a holdings history, do not wait for monthly N-PORT.** Publication is quarterly on 8 October 2026,
monthly publication is delayed to November 2027 at the earliest, and the SEC has proposed keeping it
quarterly. A dated archive of daily issuer files is something you start collecting yourself or buy.
For overlap and look-through, [ETF research tools](https://stockmarketstack.com/categories/etf-research) differ mainly in which
of these files they read and how old it is — [ETF Research Center and ETF Insider](https://stockmarketstack.com/compare/etf-research-center-vs-etf-insider)
are compared on exactly that.

## Tools this bears on

- [ETF Research Center](https://stockmarketstack.com/tools/etf-research-center.md) — Holdings-level ETF research — overlap, stock locator and fundamentals rolled up per fund.
- [ETF Insider](https://stockmarketstack.com/tools/etf-insider.md) — Look-through overlap, concentration and correlation for a portfolio of US funds.
- [Trackinsight](https://stockmarketstack.com/tools/trackinsight.md) — A free global ETF screener — 15,875 funds across listing venues, with daily flows.
- [ETF.com](https://stockmarketstack.com/tools/etf-com.md) — A free US ETF screener, flows tool and fund pages on FactSet data, with an AI assistant.

## FAQ

### Why is an ETF's price different from its NAV?

Because they are measured differently. NAV is the value of the fund's holdings per share, computed once a day, normally at the 4 p.m. Eastern close; the price is what buyers and sellers agreed on the exchange. Authorised participants can create or redeem shares in large blocks when the two drift apart, which usually keeps the gap small, but nothing forces it to zero.

### What is iNAV or IIV?

An intraday estimate of an ETF's value per share, recomputed during the trading day. The SEC declined to require one when it adopted Rule 6c-11 in 2019, saying it can be stale or inaccurate for funds holding foreign securities or less liquid bonds and that market makers compute their own values from the daily holdings instead.

### How often do ETFs disclose their holdings?

An ETF that relies on SEC Rule 6c-11, as most US ETFs do, must publish its full holdings on its website every business day, before the market opens. Unit investment trusts such as SPY, share-class ETFs such as Vanguard's VOO and non-transparent ETFs are outside the rule and set their own schedule; SPY publishes daily, while on 8 October 2026 VOO's page showed holdings as of 31 August. The SEC's own copy, from Form N-PORT, is public only for the last month of each fiscal quarter and up to 60 days after it.

### Is the SEC switching N-PORT holdings to monthly publication?

It adopted monthly publication in August 2024, delayed it in April 2025 to 17 November 2027 for fund groups with $1 billion or more in net assets and 18 May 2028 for smaller ones, and on 18 February 2026 proposed restoring quarterly publication instead. On 8 October 2026 the SEC's rulemaking page listed the proposal and no final rule.

### Why do two websites show different holdings for the same ETF?

Usually because the files describe different dates — yesterday's close from the issuer, a month end or a quarter end from a vendor or the SEC. After that, cash and futures lines, the price used to turn share counts into weights, and whether the figure is the fund's or one share class's all move the numbers.

## Sources

1. [17 CFR 270.6c-11, Exchange-traded funds](https://www.law.cornell.edu/cfr/text/17/270.6c-11) — Legal Information Institute, Cornell Law School, read 2026-10-08
2. [Exchange-Traded Funds, final rule (84 FR 57162)](https://www.govinfo.gov/content/pkg/FR-2019-10-24/html/2019-21250.htm) — Securities and Exchange Commission, 2019-10-24. Rule 6c-11 is still in force as adopted here; the SEC's February 2026 N-PORT proposal cites its daily holdings condition as current.
3. [Exchange-Traded Funds, final rule (Release No. 33-10695), SEC copy](https://www.sec.gov/files/rules/final/2019/33-10695.pdf) — Securities and Exchange Commission, 2019-09-25. The adopting release of Rule 6c-11, cited for its scope (pp. 17 and 122); the rule has not been re-adopted.
4. [Form N-PORT and Form N-CEN Reporting, final rule (Release No. IC-35308)](https://www.sec.gov/files/rules/final/2024/ic-35308.pdf) — Securities and Exchange Commission, 2024-08-28
5. [Form N-PORT and Form N-CEN Reporting, delay of effective and compliance dates (Release No. IC-35538)](https://www.sec.gov/files/rules/final/2025/ic-35538.pdf) — Securities and Exchange Commission, 2025-04-16
6. [Form N-PORT Reporting, proposed rule (91 FR 8582)](https://www.govinfo.gov/content/pkg/FR-2026-02-23/pdf/2026-03460.pdf) — Securities and Exchange Commission, 2026-02-23
7. [Form N-PORT Reporting, rulemaking page (File No. S7-2026-05)](https://www.sec.gov/rules-regulations/2026/02/s7-2026-05) — Securities and Exchange Commission, read 2026-10-08
8. [NYSE Arca notice of proposed rule change, SR-NYSEArca-2020-56 (Release No. 34-89197)](https://www.sec.gov/rules/sro/nysearca/2020/34-89197.pdf) — Securities and Exchange Commission, 2020-06-30. Cited only for the Commission's description of Managed Portfolio Shares, which it quotes; that description has not been withdrawn.
9. [iShares Core S&P 500 ETF (IVV), fund page](https://www.ishares.com/us/products/239726/ishares-core-sp-500-etf) — BlackRock (iShares), read 2026-10-08
10. [State Street SPDR S&P 500 ETF Trust (SPY), fund page](https://www.ssga.com/us/en/intermediary/etfs/spdr-sp-500-etf-trust-spy) — State Street Global Advisors, read 2026-10-08
11. [Portfolio holdings disclosure policy](https://investor.vanguard.com/legal/portfolio-holdings-disclaimer) — Vanguard, read 2026-10-08
12. [Vanguard S&P 500 ETF (VOO), fund page for advisors](https://advisors.vanguard.com/investments/products/voo/vanguard-sp-500-etf) — Vanguard, read 2026-10-08
13. [SPY fund page](https://www.etf.com/SPY) — ETF.com, read 2026-10-08
14. [SPY holdings](https://www.trackinsight.com/en/fund/SPY/holdings) — Trackinsight, read 2026-10-08
15. [FAQ](https://etfinsider.co/faq/) — ETF Insider, read 2026-10-08
16. [SPY fund page](https://www.etfrc.com/SPY) — ETF Research Center, read 2026-10-08
17. [iShares Core MSCI World UCITS ETF (IE00B4L5Y983), ETF profile](https://www.justetf.com/en/etf-profile.html?isin=IE00B4L5Y983) — justETF, read 2026-10-08
18. [ETF constituents, tutorial](https://www.justetf.com/en/tutorial/etf-search/etf-constituents.html) — justETF, read 2026-10-08
19. [UCITS Questions and Answers, 42nd Edition, ID 1012](https://www.centralbank.ie/docs/default-source/regulation/industry-market-sectors/funds/ucits/guidance/42nd-edition-ucits-qa.pdf) — Central Bank of Ireland, 2025-04-17
20. [Guidelines on ETFs and other UCITS issues (ESMA/2014/937)](https://www.esma.europa.eu/sites/default/files/library/2015/11/esma-2014-0011-01-00_en_0.pdf) — European Securities and Markets Authority, 2014-08-01. The guidelines ESMA still publishes for UCITS ETFs; paragraph 17 on portfolio transparency has not been amended.

*Last updated 2026-10-09. A reference page, corrected in place — not a dated post.*