Total stablecoin market capitalisation reached $323.411 billion in May 2026, with USDT dominance at 58.65% and a 7-day change of +$589.12 million across the index. Behind that float sits a transparency layer that has tightened sharply since 2024, driven by the GENIUS Act in the United States and MiCA Title III in the European Union.
Reserve attestations are now monthly minimums under both regimes. Circle publishes USDC reserve holdings weekly with a Big Four monthly attestation; Tether refreshes USD₮ circulation daily and a BDO Italia reserve report quarterly. The data below covers issuer balances, audit cadences, statutory requirements, and the on-chain composition behind each peg.
Key Takeaways
- The total stablecoin market reached $323.41 billion in May 2026, with USDT holding 58.65% dominance and USDC trailing at $77.00 billion.
- USDC reserves total $76.7 billion against $76.5 billion in circulation, with Deloitte & Touche LLP providing monthly Big Four attestation since fiscal 2022.
- USDT net circulation reached $189.77 billion as of May 13, 2026, with Tether’s Q1 2026 attestation reporting total assets of $191.77 billion and net equity of $8.23 billion.
- The GENIUS Act, signed July 18, 2025, requires 100% reserve backing in U.S. dollars or short-term Treasuries plus monthly public composition disclosures.
- MiCA Article 36 requires EU issuers to publish reserve composition at least monthly, with the EBA setting deposit floors no lower than 30% for non-significant tokens and 60% for significant asset-referenced tokens.
- PayPal USD (PYUSD) attestations moved from WithumSmith+Brown, PC to KPMG LLP on February 28, 2025, completing Paxos’s migration to a Big Four auditor.
- Of Tether’s $189.77 billion USDT net circulation, $184.30 billion sits on Ethereum and Tron, a chain concentration that token-level attestations do not measure.
Editor’s Choice
- USDT net circulation: $189.77 billion (May 13, 2026, Tether Transparency dashboard).
- USDC in circulation: $76.5 billion with $76.7 billion in total reserves (Circle Transparency, May 2026).
- Tether Q1 2026 total assets: $191.77 billion; net equity $8.23 billion (BDO Italia attestation, March 31, 2026).
- USDC 365-day issuance: $291.3 billion issued against $275.3 billion redeemed, a +$16.0 billion net change in circulation.
- Total stablecoin market cap: $323.41 billion, with a 30-day change of +0.63% (DefiLlama, May 2026).
- USDT on Ethereum: $95.84 billion net circulation; USDT on Tron: $88.46 billion net circulation.
- EURC in circulation: €385.8 million with €388.5 million in total reserves (Circle Transparency, May 2026).
Recent Developments
- May 13, 2026: Tether refreshed USD₮ net circulation to $189,773,652,765.49, extending its daily disclosure cadence into the 14-chain footprint that now includes Aptos, Ton, Avalanche, Kaia, Celo, and Near.
- May 11, 2026. Circle secured fresh financing from BlackRock and A16z to build out its Arc settlement initiative, deepening the existing relationship that already routes part of USDC’s reserve into the BlackRock-managed Circle Reserve Fund.
- May 8, 2026. Tether published a public address freeze action across hundreds of wallets, demonstrating the seize-freeze-burn technical capability that the GENIUS Act now requires of every U.S.-licensed payment stablecoin issuer.
- May 1, 2026. Tether published its Q1 2026 attestation reporting profit above $1 billion with net equity at $8.23 billion, with the cutoff date set at March 31, 2026, and BDO Italia preparing the report.
- April 29, 2026. Visa expanded its stablecoin settlement footprint to nine blockchains, broadening the rail base that consumes USDC and other dollar-pegged tokens for merchant payouts.
- March 17, 2026. PayPal extended PYUSD availability to 70 countries, expanding the regulated stablecoin issued by Paxos Trust Company that now sits under KPMG LLP’s monthly attestation.
What Stablecoin Reserves Are
A stablecoin reserve is the off-chain pool of assets backing every token in circulation. Composition determines whether the peg holds under redemption stress and whether the issuer can satisfy regulatory liquidity tests. Three reserve archetypes dominate the market today.
- Cash + short-term Treasury bills is the USDC model: Circle holds USDC reserves in Other Bank Deposits, Deposits at Systemically Important Institutions, Overnight Reverse Treasury Repo, and <3-Month Treasuries, with Treasury exposure routed through a 2a-7 money market fund.
- A diversified balance sheet is the USDT model. The Tether Issuer’s assets exceed its liabilities, with the bulk held in short-dated U.S. Treasuries.
- Bank-trust deposits are the Paxos model. PayPal USD (PYUSD) is issued by Paxos Trust Company N.A., a New York DFS-supervised trust company.
| Reserve component | USDC (Circle) | USDT (Tether) | PYUSD (Paxos) |
|---|---|---|---|
| Short-term Treasuries | Yes (<3-month) | Yes (majority of book) | Yes |
| Bank deposits at SIIs | Yes (segregated) | Yes | Yes (trust deposits) |
| Overnight reverse repo | Yes | Yes | Yes |
| Money market fund vehicle | Circle Reserve Fund (USDXX, 2a-7) | None disclosed | None disclosed |
| Off-balance-sheet auditor | Deloitte & Touche LLP | BDO Italia | KPMG LLP |
Source: Circle Transparency, Tether Transparency, Paxos Transparency Reports.
Under MiCA Title III, issuers of asset-referenced tokens that invest a part of the reserve of assets must hold those investments only in highly liquid financial instruments with minimal market risk, credit risk, and concentration risk, capable of being liquidated rapidly with minimal adverse price effect.
USDC Reserve Composition and Cadence
Circle runs the most layered disclosure stack of any major issuer. The headline numbers refresh weekly; a Big Four firm signs a monthly attestation; the BlackRock-managed Circle Reserve Fund publishes its own holdings; and Circle itself files quarterly with the SEC as a public company.
- USDC in circulation: $76.5 billion as of May 15, 2026.
- Total reserves: $76.7 billion, slightly exceeding circulation by design.
- Disclosure cadence: reserve holdings disclosed on a weekly basis, with associated mint and burn flows.
- Attestation cadence: monthly third-party assurance by a Big Four accounting firm, prepared under AICPA attestation standards.
- Auditor: Deloitte & Touche LLP has audited Circle’s financials since fiscal 2022, replacing Grant Thornton LLP, which had served as Circle’s independent auditor from 2015.
- Reserve fund vehicle: the Circle Reserve Fund is a 2a-7 money market fund managed by BlackRock, holding part of the Treasury and overnight reverse repo positions.
- EURC reserves: €385.8 million in circulation against €388.5 million in total reserves.
| Window | Issued | Redeemed | Net change in circulation |
|---|---|---|---|
| 7 days | $5.4 billion | $7.1 billion | -$1.7 billion |
| 30 days | $23.4 billion | $25.5 billion | -$2.1 billion |
| 365 days | $291.3 billion | $275.3 billion | +$16.0 billion |
Source: Circle Transparency dashboard.
The USDC issuance dashboard exposes flow volumes that token-level supply alone hides. Over the trailing 365 days, USDC saw $291.3 billion issued and $275.3 billion redeemed, a turnover roughly 3.8 times the standing float.
By the numbers: Over $291 billion of USDC was issued in the trailing year against $275 billion redeemed, generating annual gross flows of about $566 billion through the same trust banks that supervisors monitor under the GENIUS Act monthly disclosure rule.
Tether USDT Attestations and Quarterly Reports
Tether sits at the other end of the disclosure spectrum from Circle: daily circulation snapshots, quarterly reserve reports, and a continental-European auditor rather than a Big Four firm.
- USD₮ net circulation: $189,773,652,765.49 as of May 13, 2026, 11:30 PM UTC.
- Quarterly attestation cadence: Tether Issuer Assets and Liabilities published as of the last Reserves Report (31 March 2026): Total Assets $191,767,741,495.00, Total Liabilities $183,535,531,717.00, Net Equity $8,232,209,778.00.
- Auditor: BDO Italia provides quarterly attestation reports.
- Daily refresh: Tether tokens in circulation metrics are typically refreshed daily, a cadence that exceeds both GENIUS Act and MiCA monthly minimums.
- Token coverage: USD₮, CNH₮ (wound down February 20, 2027), MXN₮, XAU₮ (707,747.09 ounces of gold backing the gold token).
- Backing model: all Tether tokens are pegged at 1-to-1 with a matching fiat currency and are backed 100% by Tether’s Reserves.
- BSA application: U.S. issuers now operate under the same anti-money-laundering (AML) program design rules that banks face, including SAR filings, OFAC sanctions screening, and customer identification programs. The seize-freeze-burn capability is now a technical control rather than a discretionary policy commitment.
The Q1 2026 reserves report cutoff of 31 March 2026 placed Tether net equity at $8.23 billion, a buffer of roughly 4.3% of total assets that absorbs reserve-side mark-to-market volatility before holder claims are affected.
GENIUS Act: US Reserve Disclosure Rules
The GENIUS Act was signed into law by President Donald J. Trump on July 18, 2025, creating the first-ever Federal regulatory system for stablecoins. It now sets the floor for every U.S.-licensed payment stablecoin issuer.
- Reserve requirement: 100% reserve backing with liquid assets like U.S. dollars or short-term Treasuries.
- Disclosure cadence: issuers must make monthly, public disclosures of the composition of reserves.
- Marketing rules: issuers are forbidden from making misleading claims that their stablecoins are backed by the U.S. government, federally insured, or legal tender.
- AML obligations: the GENIUS Act explicitly subjects stablecoin issuers to the Bank Secrecy Act, obligating them to establish effective anti-money laundering and sanctions compliance programs with risk assessments, sanctions list verification, and customer identification.
- Insolvency priority: In the event of insolvency of a stablecoin issuer, the GENIUS Act prioritizes stablecoin holders’ claims over all other creditors.
- Technical capability: all stablecoin issuers must possess the technical capability to seize, freeze, or burn payment stablecoins.
- Federal-State alignment: the GENIUS Act aligns State and Federal stablecoin frameworks, ensuring fair and consistent regulation throughout the country.
| Provision | GENIUS Act (US) | MiCA Title III (EU) |
|---|---|---|
| Reserve backing | 100% | 100% (asset-referenced and e-money tokens) |
| Permitted assets | U.S. dollars, short-term Treasuries | Highly liquid financial instruments, minimum market/credit/concentration risk |
| Composition disclosure cadence | Monthly | At least monthly (Article 36) |
| Audit publication | Required (implied by composition disclosure) | Brief summary + full unredacted audit report on website |
| Holder priority in insolvency | Yes | Embedded via segregation rules |
| BSA / AML coverage | Yes (explicit) | Yes (via AMLD6 + national transposition) |
Source: White House GENIUS Act fact sheet, Markets in Crypto-Assets Regulation.
MiCA Title III: EU Reserve Standards
The Markets in Crypto-Assets Regulation, EU (MiCA), applies under Title III to asset-referenced tokens and Title IV to e-money tokens, and explicitly extends to so-called algorithmic stablecoins that aim to maintain a stable value in relation to an official currency. The same regime captures algorithmic stablecoins inside the same regulatory perimeter even when the stabilisation mechanism is protocol-based.
- Scope clause: where a crypto-asset falls within the definition of an asset-referenced token or e-money token, Title III or IV of this Regulation should apply, irrespective of how the issuer intends to design the crypto-asset, including the mechanism for maintaining a stable value of the crypto-asset.
- Algorithmic-stablecoin scope: the same applies to so-called algorithmic ‘stablecoins’ that aim to maintain a stable value in relation to an official currency.
- Composition disclosure: issuers of asset-referenced tokens shall disclose on their website the amount of asset-referenced tokens in circulation, and the value and composition of the reserve of assets referred to in Article 36. Such information shall be updated at least monthly.
- Audit publication: issuers of asset-referenced tokens shall publish as soon as possible in a publicly and easily accessible place on their website a brief, clear, accurate, and transparent summary of the audit report, as well as the full and unredacted audit report.
- Investment restrictions: issuers shall only invest reserve assets in highly liquid financial instruments with minimal market risk, credit risk, and concentration risk; the investments shall be capable of being liquidated rapidly with minimal adverse price effect.
- Deposit floors: for significant asset-referenced tokens, the minimum amount of deposits in each official currency referenced cannot be lower than 60% of the amount referenced; for non-significant issuers, the floor is 30%.
- Technical standards delivery: MiCA mandates that the EBA shall submit the draft regulatory technical standards to the Commission by 30 June 2024.
The minimum deposit floor for significant asset-referenced tokens cannot be lower than 60% of the amount referenced in each official currency, with 30% for non-significant issuers. That tilts the EU regime toward depositor-flavoured backing for the largest tokens, in contrast with the GENIUS Act, which lets a U.S. issuer hold a higher Treasury share even at scale.
PYUSD and USDG: Paxos Issuer Disclosures
Paxos Trust Company sits at the operating layer for two regulated dollar stablecoins: PYUSD, issued for PayPal, and USDG, the Global Dollar consortium product. Both tokens publish monthly attestations.
- PYUSD auditor: KPMG LLP is an independent third-party accountant handling PYUSD attestations.
- Auditor transition: attestation reports prior to February 28, 2025, were issued by WithumSmith+Brown, PC; Withum’s examination was conducted in accordance with attestation standards established by the American Institute of Certified Public Accountants (AICPA).
- Attestation cadence: monthly, AICPA standards, posted to paxos.com/pyusd-transparency.
- Report archive: reports visible for 2026 (Jan, Feb, Mar), 2025, 2024, 2023.
- Issuer entity: Paxos Trust Company N.A., a New York DFS-supervised trust company.
- Sibling tokens: Paxos-issued assets include Global Dollar (USDG), PayPal USD (PYUSD), Pax Dollar (USDP), Pax Gold (PAXG), and BUSD.
- USDG disclosure: Paxos has a policy commitment to ensuring up-to-date attestation reports are publicly available for USDG.
The Withum-to-KPMG migration completes Paxos’s move into the Big Four orbit.
Reserve Asset Mix: Cash, Repo, Treasury Bills
Every audited issuer’s reserve sits in some combination of four buckets: cash on deposit at banks, deposits at Systemically Important Institutions, overnight reverse repurchase agreements with the Federal Reserve, and short-dated U.S. Treasury bills.
- Cash at SIIs: deposits at SIIs (defined as globally or domestically significant financial institutions and national central banks) held as reserves for the benefit of USDC holders.
- Treasury exposure: Treasuries and overnight reverse repurchase agreements (Overnight Reverse Treasury Repo) held as reserves for the benefit of USDC holders may be held by the Issuer in custodial accounts, as part of a separately managed account, or within the Circle Reserve Fund.
- BlackRock vehicle: the Circle Reserve Fund, a 2a-7 money market fund managed by BlackRock, adds a second daily disclosure layer through BlackRock’s fund holdings page.
- Tether asset spread: Total Assets $191,767,741,495.00 versus Total Liabilities $183,535,531,717.00, with the asset side disclosed quarterly.
- MiCA investment quality test: reserve investments shall be capable of being liquidated rapidly with minimal adverse price effect.
- GENIUS Act asset list: liquid assets like U.S. dollars or short-term Treasuries only.
| Reserve bucket | Liquidity profile | USDC exposure | USDT exposure | PYUSD exposure |
|---|---|---|---|---|
| Bank deposits (non-SII) | Same-day | Disclosed | Disclosed | Disclosed |
| Deposits at SIIs | Same-day | Disclosed | Disclosed | Disclosed |
| Overnight reverse repo | Overnight | Disclosed | Disclosed | Disclosed |
| <3-month Treasuries | T+1 secondary | Disclosed | Disclosed (majority) | Disclosed |
| Money market fund (2a-7) | T+1 | Yes (USDXX via BlackRock) | No public disclosure | No public disclosure |
Source: Circle Transparency, Tether Transparency, Paxos Transparency Reports.
Worth noting: Circle is the only major issuer routing reserves through a publicly traded 2a-7 money market fund (USDXX, managed by BlackRock). BlackRock publishes the fund’s holdings independently, which adds a second auditable disclosure path before Circle’s monthly attestation lands.
Chain Concentration Risk
Reserve attestations measure the issuer’s balance sheet. They do not measure where the tokens themselves live, which matters for redemption-rail risk during stress.
- Two-chain concentration: of Tether’s $189,773,652,765.49 USD₮ net circulation, approximately $184.30 billion (97.1%) sits on just Ethereum and Tron.
- Ethereum share: Net Circulation $95,836,774,173.45 (50.5% of float).
- Tron share: Net Circulation $88,458,655,005.33 (46.6% of float).
- Authorised-but-not-issued buffer: Ethereum carries $1,235,101,789.11 in authorized-but-not-issued USD₮; Tron carries $900,554,319.82, an inventory pool used to smooth chain-level demand.
- Deprecated chains: Tether is no longer issuing or obligated to redeem Tether Tokens on the Kusama, Bitcoin Cash SLP, Omni Layer, EOS, and Algorand blockchains.
- Wound-down currency: Tether has wound down and is no longer obligated to redeem EUR₮.
Key finding: USDT settlement-rail concentration on Ethereum plus Tron is 97.1% of the float. A single-chain outage of either rail would freeze redemption flows for tens of billions of dollars in tokens that the issuer’s quarterly attestation otherwise treats as a single homogeneous pool. regulatory compliance frameworks still measure issuers, not chains, which is the gap that token-level disclosure does not close.
The chain-level skew is also a redemption-priority signal. Bridge liquidity, validator decentralisation, and on-chain fee markets differ sharply between Ethereum and Tron. A redemption queue cleared at par from Circle’s monthly attestation can still face friction at the chain layer where the burns actually happen.
USDC and USDT: Head-to-Head Disclosure
The two largest fiat-backed stablecoins have converged on similar reserve composition but kept measurably different transparency stacks. Our USDC and USDT head-to-head shows the breakdown by float, chain, and venue.
- Circulation: USDC $76.5 billion vs USDT $189,773,652,765.49 (roughly 2.5x ratio).
- Reserve disclosure cadence: USDC weekly + monthly attestation; USDT daily snapshot + quarterly reserves report.
- Auditor: USDC Deloitte & Touche LLP (Big Four since FY2022); USDT BDO Italia (continental European mid-tier).
- Reserve fund vehicle: USDC routes part of reserves through Circle Reserve Fund (USDXX, BlackRock); USDT holds reserves on Tether Holdings balance sheet directly.
- Public-company status: Circle files quarterly with the SEC; Tether Holdings is private.
- Net equity/capital buffer: USDC reserves of $76.7 billion sit slightly above the $76.5 billion in circulation; USDT net equity at $8.23 billion on Tether Q1 2026 total assets of $191,767,741,495.00.
- Token-level on-chain footprint: USDC across Ethereum, Solana, Hyperliquid L1, Base, Arbitrum, Polygon; USDT across 14 chains (Ethereum + Tron + 12 smaller).
Conclusion
Stablecoin reserves transparency now rests on three reinforcing layers. The market is publicly indexed in real time at $323.411 billion, issuer disclosure cadences run from daily to monthly, and statutory minimums are set by the GENIUS Act in the United States and MiCA Title III in the European Union. Circle has used Deloitte & Touche LLP as its independent auditor since fiscal 2022 for USDC; BDO Italia prepared Tether’s Q1 2026 attestation as of 31 March 2026 for USDT; KPMG LLP is Paxos’s independent third-party accountant for PYUSD.
The next 12 months will test enforcement rather than design. GENIUS Act monthly disclosure rules apply prospectively to every U.S.-licensed issuer; MiCA Article 36 reports are already a continuous obligation; and chain-level concentration risk remains the structural gap that token-level attestations do not yet close.