USDC vs USDT (2026): Reserves, Regulation, Chains, Risks

USDC vs USDT at a glance

	USDC	USDT
Issuer	Circle (EU: Circle Internet Financial Europe SAS)	Tether International, S.A. de C.V.
Circulating (DefiLlama, 9 Oct 2026)	~$73.1B	~$183.2B
Reserve assets	Circle Reserve Fund (SEC-registered 2a-7 government MMF) plus bank cash	Mostly US Treasuries and repo; also gold, bitcoin, secured loans
Independent checks	Monthly Big Four assurance; weekly holdings disclosure	Quarterly BDO attestation; KPMG audit of 2025 accounts
MiCA (EU)	Authorised e-money token issuer since 1 Jul 2024	Not in ESMA's register
GENIUS Act (US)	Not yet licensed; Act not in force	Not yet licensed; separate US coin USAT
Largest chains	Ethereum, Hyperliquid, Solana, Base	Tron, Ethereum, BNB Chain, Solana
On Stellar	Native, ~376M (Horizon)	USDT0 only, ~5.7M (Horizon)

USDC and USDT by the numbers (October 2026)

DefiLlama counted about $311.5 billion of USD-pegged stablecoins on 9 October 2026. USDT accounted for $183.2 billion (58.8%) and USDC for $73.1 billion (23.5%). A year earlier the figures were about $178.1 billion and $75.3 billion, so USDT grew slightly while USDC shrank slightly.

Measure (9 Oct 2026)	USDC	USDT
Circulating supply (DefiLlama)	$73.1B	$183.2B
Share of USD stablecoins	23.5%	58.8%
Supply on 9 Oct 2025 (DefiLlama)	$75.3B	$178.1B
Chains tracked by DefiLlama	157	130
Largest chain	Ethereum, $45.3B	Tron, $92.4B
On Stellar	~$376M (10th chain for USDC)	None native; ~5.7M USDT0

Issuers' own figures differ slightly from DefiLlama's: Circle reported $74.1 billion of USDC on 5 October, and Tether reported about $184.6 billion of USDT issued at 30 June. DefiLlama's chain count includes bridged versions; Circle says USDC is natively issued on 38 blockchains. For the whole market, see the stablecoin market in 2026.

How to choose

• You trade on centralised exchanges or use Tron: USDT is where the liquidity is; Tron alone carries $92.4 billion of it.
• You want the simplest reserve to reason about: USDC's reserve is a government money market fund and bank cash, published weekly.
• You are in the EU or serve EU users: USDC (and Circle's euro coin, EURC) is issued under MiCA; USDT is not.
• You are on Stellar: use native USDC from Circle's issuer; check the issuer before accepting anything labelled USDT.

USDC — Circle's fund-backed dollar

USDC is Circle's dollar stablecoin. Circle says most reserves sit in the Circle Reserve Fund (USDXX), an SEC-registered 2a-7 government money market fund managed by BlackRock, with the rest as cash at large banks. A Big Four firm gives monthly assurance that reserves exceed USDC in circulation.

Circle describes the fund as holding cash, short-dated US Treasuries and overnight Treasury repurchase agreements, and BlackRock publishes daily third-party reporting on its portfolio. Circle discloses reserve holdings and mint and burn flows weekly. Deloitte & Touche has audited Circle's own financial statements since fiscal year 2022; the monthly reserve report is a separate assurance engagement under AICPA attestation standards.

In the EU, Circle Internet Financial Europe SAS received an electronic money institution licence from France's ACPR on 1 July 2024, the day MiCA's stablecoin rules applied, and issues both USDC and EURC as e-money tokens. Its USDC white paper was last updated in ESMA's register on 15 September 2026. How a reserve like this keeps the price at a dollar is covered in how stablecoins hold their value.

USDT — Tether's larger, broader reserve

USDT is issued by Tether International, S.A. de C.V. Its Q2 2026 attestation by BDO put total assets at $187.75 billion against liabilities of $183.64 billion on 30 June 2026, a $4.11 billion buffer. Most reserves are US government instruments, but Tether also holds gold, bitcoin and secured loans.

Tether's own summary of the quarter says the majority of reserves "remain in U.S. government-backed instruments and short-term liquidity facilities", that it cut secured lending by about $2.38 billion and that it added 14 tons of physical gold. The buffer had been $8.23 billion at the end of Q1; Tether's Q2 release describes the quarter as one of "significant volatility across gold and Bitcoin".

Tether's reporting has improved. On 13 August 2026 it announced that KPMG had issued an unqualified opinion on its financial statements for 2025, its first full audit, reporting reserves above liabilities by $6.814 billion at year end. Attestations remain quarterly, against Circle's monthly cycle.

Tether also uses its power to freeze. On 28 September 2026 it said it had supported nearly $550 million of Iran-linked USDT freezes. Circle can restrict accounts too, which on Stellar shows as the revocable flag on its issuer.

Regulation — GENIUS Act and MiCA status

Neither coin is yet licensed under the US GENIUS Act, which takes effect on 18 January 2027. In the EU, Circle is an authorised e-money token issuer under MiCA and Tether is not. The rules differ most on reserves: GENIUS permits cash, deposits, short Treasuries and government money funds, not gold or bitcoin.

The GENIUS Act (Public Law 119-27) takes effect on the earlier of 18 months after enactment or 120 days after final regulations. The Federal Register showed only proposals and one procedural interim rule as of 9 October, so 18 January 2027 governs. From 18 July 2028, US digital asset service providers may only offer stablecoins from permitted issuers, or from foreign issuers in jurisdictions the Treasury finds comparable and registered with the OCC. Details are in the GENIUS Act, explained.

Tether's response is two products. In January 2026 it launched USAT, "developed specifically to operate within" the GENIUS framework and issued by Anchorage Digital Bank, N.A., while saying USDT "continues to operate globally" and is "progressing towards GENIUS Act compliance". In Europe, Tether stopped supporting its euro coin EURT in November 2024, citing the evolving rules. The two regimes are compared in MiCA vs the GENIUS Act.

Chains — where each one lives

USDT is concentrated on Tron ($92.4 billion) and Ethereum ($72.9 billion), with BNB Chain third. USDC is led by Ethereum ($45.3 billion), then Hyperliquid, Solana and Base. The split reflects use: USDT for exchange and peer-to-peer payments, USDC more for DeFi and on-chain applications.

#	USDC chain	Supply	USDT chain	Supply
1	Ethereum	$45.3B	Tron	$92.4B
2	Hyperliquid L1	$7.1B	Ethereum	$72.9B
3	Solana	$6.7B	BNB Chain	$9.2B
4	Base	$4.4B	Solana	$2.9B
5	Arbitrum	$2.4B	Arbitrum	$0.8B

Source: DefiLlama, 9 October 2026. A coin on a chain where it is bridged rather than native carries the bridge's risk as well as the issuer's.

On Stellar — native USDC, bridged USDT0

Circle issues USDC natively on Stellar. Horizon showed about 376M USDC on 9 October 2026: 295.6M in accounts, 75.4M in smart contracts and 5.0M in classic liquidity pools, across about 2.49M trustlines. DefiLlama's figure, about $379M, ranks Stellar 10th for USDC; its chain series shows about $237M a year earlier.

USDT on Stellar exists only as USDT0, the LayerZero OFT version of USDT, which launched on the network on 2 September 2026. USDT0's documentation lists the classic asset USDT0:GATI…JHN6Q and a Soroban token contract. Horizon showed about 2.81M USDT0 in accounts and 2.91M in contracts on 9 October, about 5.7M in total. Its biggest Aquarius pool, USDT0/USDC, held about $71K.

Two practical checks. First, Horizon lists many fake assets coded USDT and USDC, some with millions of tokens and hundreds of trustlines; the real USDC issuer is GA5Z…KZVN with home domain circle.com. Second, a bridged token adds risk: if the bridge's contracts or messaging fail, the token can lose its backing even if Tether's reserves are fine. To move USDC onto Stellar, see how to bridge USDC to Stellar; for where it earns, see USDC yield on Stellar.

Risks that apply to both

Both coins depend on an issuer honouring redemptions, on banks and custodians holding the reserve, and on the issuer's power to freeze. Neither is deposit-insured. For on-chain users, the bigger day-to-day risks are often fake tokens, bridges and the DeFi protocols the coins are deposited into.

• Reserve risk: USDC's is concentrated in one fund and a handful of banks; USDT's includes assets whose prices move, and its buffer fell from $8.23 billion to $4.11 billion between the end of Q1 and the end of Q2 2026.
• Redemption access: most holders cannot redeem directly with either issuer and rely on the market price.
• Freezes: both issuers can block addresses or trustlines.
• Platform risk: deposits in lending and AMM contracts add smart-contract risk; see DeFi risks.

How these fit together

USDT is a global payments rail backed by a large, diversified and now audited balance sheet. USDC is a narrower product built around a regulated money fund and frequent reporting, which is why it fits the EU and US rulebooks more easily. On Stellar, network design and Circle's native issuance make USDC the working dollar; USDT0 gives USDT users a route in but has a few million tokens so far.

The takeaway

Choose by where you are and what you need. For exchange liquidity, USDT. For reserve simplicity, monthly reporting and EU access, USDC. For Stellar, native USDC from Circle's issuer, and treat anything else labelled USDT with care until you have checked the issuer.

Sources: DefiLlama stablecoins API (9 Oct 2026); Horizon asset records for Circle's USDC issuer and USDT0 (9 Oct 2026); docs.usdt0.to deployments; crypto.news (2 Sep 2026); Aquarius pool API (9 Oct 2026); circle.com/usdc and /transparency (5 Oct 2026); Circle press release (1 Jul 2024); ESMA interim MiCA register (7 Oct 2026); Tether Q2 2026 attestation release (31 Jul 2026), KPMG audit release (13 Aug 2026), USAT launch (27 Jan 2026), EURT notice (27 Nov 2024) and freeze update (28 Sep 2026); GENIUS Act, Public Law 119-27; Federal Register API.