Why we use USDC (and where EURC fits)

The stablecoin market was worth about $314 billion in October 2026 (DefiLlama), but for a European saver one question matters: which stablecoin can you rely on for your savings? The short answer: the one with the clearest reserves and oversight.

This article explains why unflat chose USDC, how it differs from the alternatives, and what EURC, Circle’s euro stablecoin, is.

Are all stablecoins the same?

No. A stablecoin is designed to hold a stable value, usually one dollar or one euro, but how well it does depends on what backs it: cash and government debt held with regulated institutions, an algorithm, or vague promises. That backing is what separates a stablecoin you can save in from an experiment.

In May 2022, the market learned this the hard way. UST, an “algorithmic” stablecoin with no real reserves, collapsed within days, and its holders lost billions. Without real collateral that can be checked, a stablecoin is not money.

That is why the choice of stablecoin is not a technical detail. It is the most important decision a savings app makes.

What makes USDC different from USDT and DAI?

USDC’s issuer, Circle, backs it with cash and short-dated US Treasuries, publishes the reserves every week and has them checked every month by a Big Four accounting firm. USDT is larger but has a history of unclear reserves. DAI is decentralised and does not depend on one company, but it is more complex and much smaller.

USDT and USDC together make up about 82% of the stablecoin market (DefiLlama, October 2026).

USDC is the stablecoin we chose. Circle issues it, and about $74 billion was in circulation on 5 October 2026 (Circle). Its reserves are cash and cash equivalents: short-dated US Treasury bills, overnight repurchase agreements backed by Treasuries, and cash at regulated banks. Most of them sit in the Circle Reserve Fund, an SEC-registered money market fund managed by BlackRock. Every month, a Big Four accounting firm checks that the reserves are worth more than the USDC in circulation. The full breakdown is in our guide to stablecoins in 2026.

Circle Internet Financial holds a virtual currency licence (BitLicense) from the New York State Department of Financial Services, and in the EU Circle issues USDC and EURC as an electronic money institution authorised by the French regulator ACPR (Circle licenses). This means ongoing supervision and rules on reserves.

You can check USDC reserves yourself on Circle’s transparency page.

USDT (Tether) is the largest stablecoin, with about $184 billion in circulation in October 2026 (DefiLlama). For years, though, Tether gave limited and unclear information about its reserves. In October 2021, the US Commodity Futures Trading Commission fined Tether $41 million for misleading statements about them, and in February 2021 Tether and Bitfinex paid $18.5 million to settle with the New York Attorney General. Transparency remains its weak point compared with USDC.

DAI is decentralised: it does not depend on a single company. The trade-off is that it is harder to understand and much smaller, with about $4.8 billion in circulation in October 2026 (DefiLlama).

How does unflat put USDC to work?

Money you move to Savings is lent on Morpho, an overcollateralised lending market: every loan is backed by collateral worth more than the loan. Third-party curators, today Steakhouse Financial and Gauntlet, run the vaults, and borrowers pay the interest that becomes your yield. The lending market sets the rate, not unflat.

Morpho is one of the largest DeFi lending markets (the largest is Aave), with more than $16 billion in deposits in October 2026 (Morpho) and more than 30 published security audits. The result: about 5% a year so far in 2026, variable. That is the average annual percentage yield of unflat Savings (USDC) without cover, from 1 January to September 2026; past rates do not predict future ones. Interest accrues every second, and you withdraw whenever you want.

unflat is a technology platform and is not a bank or a financial intermediary. Funds deposited through unflat are not covered by deposit guarantee schemes (FITD or equivalent) and are subject to risk, including loss of principal. Never deposit money you cannot afford to lose.

USDC, with reserves you can check, and Morpho, audited and overcollateralised, are the two foundations unflat builds on. More in the story behind unflat.

What is EURC, the euro stablecoin?

EURC is the euro stablecoin issued by Circle, the issuer of USDC: 1 EURC is designed to be worth 1 euro, with reserves held at regulated financial institutions in the European Economic Area. It is issued under MiCA, and on 5 October 2026 about €422 million was in circulation, more than half of all euro stablecoins.

USDC is our choice today. EURC is the euro stablecoin from the same issuer, and it is worth knowing.

In July 2024, Circle became the first global stablecoin issuer to comply with MiCA, the EU’s crypto-asset regulation, whose stablecoin rules have applied since 30 June 2024. Its French e-money licence is the basis of that compliance, and Circle’s MiCA licence extends across the EU.

MiCA also reshaped the market. Binance removed USDT spot trading for users in the European Economic Area at the end of March 2025, and Tether stopped supporting EURT, its euro stablecoin, in November 2024.

In January 2026, Ingenico announced stablecoin payments, EURC included, on millions of its payment terminals through WalletConnect Pay.

Why hold a balance in dollars if you think in euros?

Because it adds the world’s main currency to money that is otherwise all in euros. The dollar is on one side of 89% of all currency trades (BIS, April 2025) and makes up 56.70% of central bank reserves worldwide (IMF, second quarter of 2026). On unflat your balance is in USDC, so you hold dollars without opening a US account.

For most people in Europe, everything is in euros: salary, bank account, home, pension. A part in dollars means that part no longer depends on the euro alone. It is the same reason central banks keep reserves in more than one currency.

USDC is also a dollar that travels. Circle redeems it 1:1 for US dollars, and issues it natively on 38 blockchain networks (Circle, September 2026). On unflat you can send it to another account you control, not only back to your bank.

	Dollars	Euros
Share of central bank reserves (IMF, Q2 2026)	56.70%	20.6%
Share of currency trades, on one side (BIS, April 2025)	89%	28.9%

Source: IMF, COFER data, published 30 September 2026; BIS, Triennial Central Bank Survey, September 2025. Currency trades sum to 200% because every trade has two currencies.

What happens to your balance when the dollar rises or falls?

When the dollar strengthens against the euro, your balance is worth more in euros, on top of the interest. When the dollar weakens, it is worth less. From January 2021 to September 2022 the dollar rose, and 1,000 USDC went from about €822 to €1,010 (ECB monthly averages). In 2025 the move went the other way.

The path of the money is short. The euros you add by card or bank transfer are converted into USDC by MoonPay or Coinbase. The balance and the interest stay in USDC. When you withdraw, MoonPay or your Coinbase account turn them back into euros. The app can show your balance in euros, and that figure moves with the exchange rate.

An example with round numbers, before fees and interest: you add €1,000 when €1 buys $1.10, and get about 1,100 USDC.

Rate when you withdraw	What 1,100 USDC is worth	Effect of the exchange rate
€1 = $1.00 (the dollar strengthened)	€1,100	+€100
€1 = $1.10 (unchanged)	€1,000	€0
€1 = $1.20 (the dollar weakened)	€917	−€83

Illustrative figures, not a forecast. The rate has moved by that much in recent years, in both directions:

Period	Dollars per euro (ECB reference rate)	1,000 USDC in euros
January 2021 → September 2022, monthly averages	1.2171 → 0.9904	€822 → €1,010
January 2025 → September 2025, monthly averages	1.0354 → 1.1732	€966 → €852
Last 12 months: high on 28 January 2026, low on 7 October 2026	1.1974 and 1.1177	€835 and €895
16 October 2026	1.1253	€889

Source: European Central Bank, euro reference exchange rates against the US dollar, October 2026.

You choose when to go back to euros: there is no lock-up, and you withdraw whenever you want. unflat charges no fees; MoonPay and Coinbase may charge for card and bank payments, and you see it before you confirm. If you need a set amount in euros on a set date, keep that part in euros: options such as a deposit account or government bonds are compared in DeFi vs traditional banks. The other risks, and who can move your money, are in where your money sits on unflat.

How to check it yourself

• Deposits, yield and cover on unflat are public on the Base blockchain, a network built on Ethereum.
• Circle publishes USDC reserves every week, and the monthly reports of a Big Four accounting firm, on its transparency page.
• Morpho lists the audits of its contracts in its documentation.
• unflat’s technical documentation is public.

To see who can move your money, read where your money sits on unflat, or browse our guides.

Conclusion

Among the large stablecoins, USDC has the clearest reserves and oversight. We do not promise returns: the rate is variable and the market sets it. What we can show you is the foundation your savings stand on.