# Where stablecoin reserve data comes from

When a dashboard calls a stablecoin fiat-backed, which document says so, who examined it, as of when, and what the law will require. Read before you rely on it.

*https://cryptomarkets.tools/guides/where-stablecoin-reserve-data-comes-from · background to Crypto Fundamentals & Research*

**Answer:** A dashboard's "fiat-backed" label is a classification, not a finding. The finding is in an issuer's reserve report and an accountant's opinion on it, and each states its scope: a point in time, an assertion, an excluded note. Tether publishes a quarterly ISAE 3000 assurance report from BDO; Circle a monthly AICPA examination. The GENIUS Act will require a monthly composition report examined by a registered accounting firm; it is not in effect yet.

A stablecoin row on a dashboard usually carries a word — fiat-backed, crypto-backed, algorithmic —
and a reader takes that word as a fact about the reserve. It is not. It is a category the dashboard
assigned. The facts about a reserve are in three other places: a report the issuer prepares, an
opinion an accountant signs on that report, and the law that decides which of those must exist and
how often. Each one states what it covers, and the scope is where readers go wrong.

This page does not say whether any token is backed. It says which document makes which claim, as of
when, and what each one leaves out.

## How it works

The chain runs in one direction.

1. **The issuer prepares a report.** Tokens outstanding, reserve assets, their value, sometimes a
   composition table. It is management's document.
2. **An accounting firm reports on it.** Not on the token and not on the company in general: on that
   report, or on one assertion in it, at the dates it names, against criteria the report itself
   sets out.
3. **Someone republishes the result.** A dashboard, an aggregator, a news item. By this stage the
   scope and the date have usually fallen off.

The dashboard's own label is a fourth thing again. DefiLlama's stablecoins API, read on 23 October
2026, lists 425 tokens, each with a `pegMechanism` field: 146 are classified as `fiat-backed`, 27
as `algorithmic` and the rest as crypto-backed. The field describes the design. It carries no
report, no accountant and no date, and it is not meant to.

## What the two largest issuers publish

### Tether: quarterly, ISAE 3000, one point in time

The most recent report on Tether's reserves is BDO Advisory Services S.r.l.'s assurance report,
signed in Milan on 31 July 2026, on the Financial Figures and Reserves Report of Tether
International, S.A. de C.V. as at 30 June 2026. Read what kind of document it is before reading the
numbers:

- **The standard.** A "reasonable assurance engagement" under the International Standard on
  Assurance Engagements 3000 (Revised), the IAASB standard for "Assurance Engagements Other than
  Audits or Reviews of Historical Financial Information". It is not an audit of financial statements,
  and its title says so.
- **The subject.** The reserves report only. The report itself says it "does not represent the
  financial statements of the Company but discloses financial information extracted from its
  accounting records".
- **The opinion.** That the report "is, in all material respects, fairly presented in accordance
  with the criteria, including Management's Key Accounting Policies, set out therein".
- **The figures it covers.** Reserves of US$187,751,426,411; liabilities of US$183,641,897,215, of
  which US$183,622,105,630 relate to digital tokens issued; an excess of US$4,109,529,196 — all as
  of 30 June 2026 at 11:59 pm UTC.

And what it says it does not cover, in its own words: "We did not perform procedures or provide any
assurance at any other date or time". The Notes to the reserves report are "for additional
information only" and outside the engagement. The going-concern assessment is management's, and
"we do not provide any assurance in respect of such assessment". The valuation assumes "normal
trading conditions" and does not reflect "key custodians or counterparties experiencing substantial
illiquidity". And the firm was engaged not by the issuer but by a third entity the report names,
Tether Global Investments Fund SICAF SA.

Separately, Tether announced on 13 August 2026 that KPMG U.S. had issued an unqualified opinion on
Tether International's financial statements for the year ended 31 December 2025, "in accordance with
AICPA standards" in its chief executive's words. The announcement does not link the statements, and
this page did not read them; it is a different document from the quarterly report, covering a
period rather than a moment.

### Circle: monthly, AICPA examination, one assertion at two dates

Circle's transparency page describes a "Big Four accounting firm" providing monthly assurance
"prepared according to attestation standards set out by the American Institute of Certified Public
Accountants", and weekly disclosure of reserve holdings. The August 2026 report is the most recent
one linked there on 23 October 2026.

It is narrower than Tether's in one way and more granular in another.

- **The subject is one assertion**: that "the Fair Value of Assets Held in USDC Reserve is equal to
  or greater than USDC in Circulation" at the report dates. The accountants "examined management's
  assertion" and opine that the assertion "is fairly stated, in all material respects".
- **Two dates, not a month.** The report dates are 11 August and 31 August 2026, both at 11:59 pm
  UTC. Nothing between them is covered.
- **The figures.** USDC in circulation of 72,034,978,974 and 73,320,757,305; fair value of reserve
  assets of US$72,112,635,782 and US$73,398,532,613.
- **The holdings, by CUSIP.** Most of the reserve sits in the Circle Reserve Fund, which the report
  describes as "a government money market fund under Rule 2a-7 of the Investment Company Act of
  1940", listed down to the individual Treasury bill and its maturity, alongside repurchase
  agreements and cash at regulated institutions.

**"In circulation" is a defined term, and it is not on-chain supply.** The report's criteria start
from total supply on its approved blockchains — 74,147,014,220 on 11 August — and subtract tokens
that exist but are not issued to anyone (1,982,133,877), tokens restricted under a legal order
(129,865,986) and pending burns in one contract (35,383). A dashboard summing token supply across
chains will show the first number; the reserve report is measured against the second. Neither is
wrong; they are not the same quantity.

## What the law will require, and when

### United States: the GENIUS Act

Public Law 119-27, signed on 18 July 2025, sets three disclosure duties for a permitted payment
stablecoin issuer:

- **A monthly composition report**, section 4(a)(1)(C): published on the issuer's website,
  containing "the total number of outstanding payment stablecoins" and "the amount and composition
  of the reserves", "including the average tenor and geographic location of custody of each category
  of reserve instruments".
- **A monthly examination and certification**, section 4(a)(3): "each month, have the information
  disclosed in the previous month-end report … examined by a registered public accounting firm",
  with the chief executive and chief financial officer certifying the report's accuracy to the
  regulator and a knowingly false certification carrying the criminal penalties of 18 U.S.C.
  1350(c). The statute's text points to a month-end report "under paragraph (1)(D)"; the
  publication duty itself is lettered (1)(C).
- **An annual audit for the largest**, section 4(a)(10): an issuer with more than
  US$50,000,000,000 in outstanding issuance that is not already an SEC reporting company prepares
  GAAP financial statements, audited by a registered public accounting firm under PCAOB standards,
  and publishes them.

**None of this is in force yet.** Section 20 makes the Act effective on the earlier of 18 months
after enactment or 120 days after the primary federal regulators issue final regulations. The
Office of the Comptroller of the Currency issued its final rule on 21 October 2026, effective
18 January 2027, for issuers within its jurisdiction. It fixes the timing: by noon on the last day
of each month, the composition report "as of noon on the last day of the previous month", in a
template the rule sets out, and the accountant's examination report "published on the website of
the issuer at the same time". Whether the other federal and state regulators have finalised their
own rules was not checked for this page.

So the monthly and quarterly reports described above are not GENIUS Act reports. They are what the
issuers publish today, under their own criteria.

### European Union: MiCA

MiCA splits stablecoins into two kinds, with different reserve duties.

- **Asset-referenced tokens.** Article 30(1): disclose the amount in circulation and the value and
  composition of the reserve, "updated at least monthly". Article 36(9): "an independent audit of
  the reserve of assets every six months". Article 36(10): notify the result to the authority within
  six weeks of the valuation date and publish it within two weeks of that; Article 30(2): publish
  "the full and unredacted audit report". ESMA's interim register file of asset-referenced token
  issuers, last modified on 14 February 2025, had no entries when read on 23 October 2026.
- **E-money tokens**, the category for a token referencing one official currency and issued by a
  credit or e-money institution. Article 54 requires at least 30 percent of the funds received to be
  "deposited in separate accounts in credit institutions" and the rest in "secure, low-risk assets"
  in the same currency. The six-monthly audit of Article 36 applies under Article 58(1) only once
  the token is classified as significant, from the date of that decision — or under Article 58(2)
  where the home authority requires it. ESMA's e-money token register lists Circle Internet
  Financial Europe SAS, an electronic money institution supervised by the French ACPR, with white
  papers for EURC and USDC; whether either token has been classified as significant was not checked
  here.

## What it costs

Reading all of this is free; every document above is public. The cost is time and lag.

- **Lag.** Tether's report for 30 June was signed on 31 July. Circle's August report covers 11 and 31
  August and is published the following month. Under MiCA an asset-referenced token's audit can
  reach the public up to eight weeks after its valuation date. Under the OCC's rule the gap is one
  month. A dashboard showing today's supply next to the latest reserve figure is showing two
  different dates.
- **Coverage.** Every report here is about a moment, or two. None of them says anything about the
  days between, about how quickly reserve assets could be sold in a stressed market, or about
  whether redemption works for a given holder.

## What you can do about it

**Find the document behind the label.** When a dashboard says fiat-backed, go to the issuer's
transparency page and find the latest accountant's report. If there is none, the label is all
there is.

**Read four things on the first page of the report.** The standard (an ISAE 3000 assurance report,
an AICPA examination or an audit of financial statements). The subject (a reserves report, one
assertion, or full financial statements). The date or dates. What is excluded — notes, going
concern, other dates. Those four decide what the opinion is worth for your purpose.

**Match the denominator.** Before comparing a reserve figure with token supply, check how the
report defines what is outstanding. Circle's in-circulation figure excludes minted-but-unissued and
legally restricted tokens; on-chain supply on [DefiLlama](https://cryptomarkets.tools/tools/defillama) or
[Artemis](https://cryptomarkets.tools/tools/artemis) does not. The [stablecoin](https://cryptomarkets.tools/glossary/stablecoin) entry covers which tokens
those vendors count in the first place.

**Date every number you put next to another.** A reserve figure from the end of last month and a
supply figure from this morning are not a ratio. Write the as-of date of each next to it.

**Check the register, not the press release.** In the EU, ESMA's interim registers say who is an
authorised e-money or asset-referenced token issuer. In the US, from the Act's effective date, the
monthly report and the accountant's examination report are both required on the issuer's own
website; their absence after that date is itself information.

**Do not stop at "attested".** An attestation answers the question its scope states, at the dates it
states. If your question is about liquidity under stress or about redemption terms, the documents to
read are the issuer's redemption policy and, from 2027, the US regulators' rules — not the reserve
report.

## Tools this bears on

- [DefiLlama](https://cryptomarkets.tools/tools/defillama.md) — DeFi's default metric set, with the TVL definition written down in public.
- [Artemis](https://cryptomarkets.tools/tools/artemis.md) — Chain and protocol fundamentals — fees, revenue, users — one definition everywhere.
- [Token Terminal](https://cryptomarkets.tools/tools/token-terminal.md) — Protocol fundamentals as an income statement — fees, revenue, earnings, multiples.

## FAQ

### Is a stablecoin attestation the same as an audit?

No. The reports Tether and Circle publish each month or quarter are assurance engagements on a specific report or assertion at stated dates — Tether's under ISAE 3000 (Revised), Circle's under AICPA attestation standards. An audit is an opinion on a full set of financial statements for a period. The GENIUS Act asks for both, for different things: monthly examinations of the reserve report, and an annual audit for issuers above 50 billion dollars.

### Does the GENIUS Act already require monthly reserve reports?

Not yet. Section 20 makes the Act effective on the earlier of 18 months after its enactment on 18 July 2025, or 120 days after the primary federal regulators issue final regulations. The OCC issued its final rule on 21 October 2026, effective 18 January 2027. Until then, what issuers publish is voluntary or governed by other regimes.

### Why does a dashboard's stablecoin supply differ from the issuer's circulation figure?

Because they count different things. Circle's USDC in circulation, as defined in its August 2026 reserve report, is total supply on its approved blockchains minus tokens minted but not issued, minus tokens restricted by legal order, minus pending burns. On 11 August 2026 that was about 74.1 billion on chain against 72.0 billion in circulation.

### Does MiCA require a stablecoin reserve audit every six months?

For asset-referenced tokens, yes: Article 36(9). For e-money tokens — euro- or dollar-pegged tokens issued by an e-money institution — the same six-monthly audit applies only once the token is classified as significant, under Article 58(1), or where the home authority requires it. ESMA's file of asset-referenced token issuers, last modified on 14 February 2025, had no entries when read on 23 October 2026.

## Sources

1. [Public Law 119-27, the GENIUS Act — sections 4(a)(1), 4(a)(3), 4(a)(10), 13 and 20](https://www.govinfo.gov/content/pkg/PLAW-119publ27/html/PLAW-119publ27.htm) — US Government Publishing Office, 2025-07-18
2. [Implementing the GENIUS Act for the issuance of stablecoins by entities subject to the jurisdiction of the OCC — final rule, 12 CFR 15.11(e) and (f)](https://www.occ.gov/news-issuances/news-releases/2026/nr-occ-2026-92a.pdf) — Office of the Comptroller of the Currency, 2026-10-21
3. [Assurance report according to ISAE 3000R on the Financial Figures and Reserves Report of Tether International, S.A. de C.V. as at 30 June 2026](https://assets.ctfassets.net/vyse88cgwfbl/2kYf7r64h3tzwiu6F0CbUB/2997abd2f11ecea74a21528048b50707/Opinion___Report_-_Tether_International_Financial_Figure_30-06-2026.pdf) — BDO Advisory Services S.r.l., published by Tether, 2026-07-31
4. [Tether completes the largest inaugural financial audit in history](https://tether.io/news/tether-completes-the-largest-inaugural-financial-audit-in-history/) — Tether, 2026-08-13
5. [Independent accountants' report and USDC Reserve Report, report dates 11 and 31 August 2026](https://6778953.fs1.hubspotusercontent-na1.net/hubfs/6778953/USDCAttestationReports/2026/2026%20USDC_Examination%20Report%20August%2026.pdf) — Circle, read 2026-10-23
6. [Transparency & stability — USDC and EURC reserves](https://www.circle.com/transparency) — Circle, read 2026-10-23
7. [Regulation (EU) 2023/1114 (MiCA), Articles 30, 36, 54 and 58](https://publications.europa.eu/resource/celex/32023R1114) — Official Journal of the European Union, read through the Publications Office, 2023-06-09. In force; the stablecoin titles have applied since 30 June 2024. Read as published in the Official Journal, not as a consolidated version.
8. [Interim MiCA register — issuers of e-money tokens (EMTWP.csv, file of 22 October 2026) and of asset-referenced tokens (ARTZZ.csv, file of 14 February 2025)](https://www.esma.europa.eu/sites/default/files/2024-12/EMTWP.csv) — European Securities and Markets Authority, 2026-10-22
9. [Stablecoins API — peggedAssets list with pegMechanism](https://stablecoins.llama.fi/stablecoins) — DefiLlama, read 2026-10-23

*Last updated 2026-10-23. A reference page, corrected in place — not a dated post.*