USDT has $184 billion in circulation and greater global liquidity. USDC is audited monthly and complies with the GENIUS Act and MiCA. Understand the differences and when to use each one.
For most people who trade crypto, USDT and USDC do the same thing: they are equivalent to one dollar , serve to protect assets during periods of volatility, and function as a medium of exchange between assets. In day-to-day practice, they are interchangeable.
But when it comes to regulation, transparency, and security of reserves, the differences are significant. And in 2026, with the regulatory market becoming defined in the US and Europe, these differences will begin to have concrete consequences.
What are they and who issues them?
Both are centralized stablecoins pegged to the US dollar at a ratio of 1:1. This means that for every token in circulation, the issuer must hold one dollar in reserves.
USDT is issued by Tether , a private company that operated in the British Virgin Islands and transferred its main operating entity to El Salvador in January 2025. The CEO is Paolo Ardoino.
USDT circulates on more than 15 blockchains , with the majority of the volume concentrated on Tron and Ethereum . It was launched in 2014 and has been the world's largest stablecoin ever since.
USDC is issued by Circle , an American company based in New York , led by CEO Jeremy Allaire.
Circle went public on the New York Stock Exchange in June 2025, under the ticker CRCL, becoming the first major stablecoin issuer to be a listed company . USDC was launched in 2018 through a joint venture between Circle and Coinbase. Since 2023, Circle has been the sole issuer.
Size and market share
In July 2026, USDT had approximately US$184 billion in circulation, representing about 60% of the total stablecoin market . USDC was around US$73 billion, or approximately 24% of the market .
Together, they account for more than 80% of the global stablecoin market.
The reserves: what backs each token
USDT
Tether's quarterly report for Q1 2026 indicated total reserves valued at approximately US$191.8 billion. About US$141 billion are in short-term US Treasury securities (T-bills) and repurchase agreements, placing Tether among the largest private holders of US debt in the world .
The remainder is distributed among physical gold, Bitcoin, secured loans, and other investments. This diversification with assets like BTC and gold is what differentiates the composition of Tether's reserves from that of Circle.
USDC
USDC reserves are held in the Circle Reserve Fund, a money market fund managed by BlackRock, in addition to cash deposits in partner banks. The composition is more conservative: basically very short-term T-bills, overnight repurchase operations, and cash. Simpler, lower yield, less composition risk.
Transparency: the main difference
This is where the two diverge most clearly.
Circle publishes monthly attestations prepared by Deloitte and files audited financial statements with the SEC, as it is a publicly traded company. Anyone can access the reports.
Tether publishes quarterly attestations . An attestation means that an accountant has confirmed that, on a specific date, the reported reserves matched the volume of tokens in circulation. It does not cover the entire period between one attestation and the next.
Tether never conducted a full audit. In early 2026, the company hired one of the Big Four, reportedly KPMG, to conduct its first full independent audit. The results were not released as of July 2026.
Regulatory history adds context. In 2021, the CFTC fined Tether $41 million for claiming that USDT was fully backed by dollars between 2016 and 2019, when it was not during certain periods. The New York Attorney General's office closed a separate case with a $18.5 million fine that same year.
Regulation: the impact of the GENIUS Act and MiCA
In 2026, the regulatory environment changed significantly for both stablecoins.
The US GENIUS Act , enacted in 2025, restricted the issuance of payment stablecoins to companies domiciled in the US. Tether, based in El Salvador, did not qualify . In response, it launched USAT in January 2026, a separate stablecoin issued by Anchorage Digital Bank and held in custody by Cantor Fitzgerald, aimed exclusively at the US market.
The European MiCA also excluded USDT from compliance. Exchanges such as Binance, Kraken, and Coinbase have removed or restricted USDT for European users.
The USDC passed both filters. Circle was the first global issuer to comply with MiCA in 2024. In July 2026, it received approval to operate as a national trust bank in the US, under the name Circle National Trust , placing the custody of the USDC under US federal supervision.
Security: the two moments that tested parity.
Neither stablecoin has permanently lost its peg to the dollar. But both have experienced periods of stress.
The worst moment for USDC was in March 2023, when Silicon Valley Bank collapsed with $3.3 billion of Circle's reserves (about 8% of the total at the time). USDC traded near $0.87 on the weekend of the collapse , before a federal program guaranteed SVB's deposits and Circle reopened redemptions. The parity returned within days.
The worst moment for USDT was in May 2022, when the collapse of TerraUSD generated panic in the market. USDT traded near $0.95 before recovering within hours.
In both cases, parity was restored. But both episodes show that even the most solid stablecoins can experience moments of decoupling under extreme market conditions.
Revenue: How each broadcaster makes money
The business model is basically the same for both: hold reserves in T-bills, receive interest, and not pass anything on to the token holder.
Tether generated approximately US$1 billion in net profit in Q1 2026 alone . With US$191 billion in reserves yielding US Treasury bonds, the result is predictable and significant.
Circle has similar revenue, but a very different cost structure. In Q1 2026, distribution costs reached almost 60% of total revenue . Coinbase, as the main distribution partner, takes a significant share of the interest generated by the reserves. This is the price of having built most of the USDC adoption through a partner.
Which one to choose?
For most users, the choice is irrelevant. USDT and USDC are worth one dollar, are easy to exchange with each other, and are available on virtually any exchange.
The choice starts to matter in specific contexts. For those operating within American or European regulations, or working with institutions that require clear regulatory compliance, USDC has an objective advantage . For those prioritizing global liquidity , access to emerging markets, and trading volume, USDT still leads by a wide margin .
In the Brazilian market, data from the Federal Revenue Service shows that USDT accounts for approximately 90% of the reported stablecoin volume . USDC penetration in Brazil is much lower, reflecting USDT's global leadership in emerging markets where access to the American banking system is more limited.
