What is a stablecoin?

Types of stablecoins

They differ in how they hold their value. MiCA does not classify them by mechanism but by reference: if they reference a single official currency they are e-money tokens (EMTs, Art. 3(1)(7)), and if they reference another value or right, or a combination, including several currencies, they are asset-referenced tokens (ARTs, Art. 3(1)(6)).

Why an algorithmic stablecoin cannot comply as an EMT or an ART. MiCA applies the same rules to them as to any other stablecoin (Recital 41), and those rules assume backing: an EMT issuer must redeem at any time and at par value (Art. 49(4)) and, if it is an electronic money institution, keep at least 30% of the funds received in credit institutions and invest the rest in secure, highly liquid assets (Art. 54); an ART issuer must constitute and at all times maintain a reserve of assets (Art. 36(1)). A design that only expands or shrinks supply, with no reserve, does not meet those requirements.

Stablecoins and MiCA: EMTs and ARTs

Regulation (EU) 2023/1114 has applied these rules since June 30, 2024 (Art. 149(3)):

• EMT (Art. 3(1)(7)): referenced to a single official currency. To offer it to the public in the EU, the issuer must be authorized as a credit institution or an electronic money institution and must have notified and published its white paper (Art. 48). Holders may redeem at any time, at face value and free of charge (Art. 49), and, if the issuer is an electronic money institution, at least 30% of the funds received is deposited with credit institutions (Art. 54). More in EMT.
• ART (Art. 3(1)(6)): referenced to another value or right, or a combination, including several currencies. The issuer must be authorized or be a credit institution (Art. 16) and keep a reserve of assets legally segregated from its own estate (Art. 36); holders have a permanent right of redemption (Art. 39).
• Neither issuers nor crypto-asset service providers may pay interest for holding them (Arts. 40 and 50).

ESMA's interim register, checked on October 16, 2026 (last updated October 7), lists EMT white papers from 25 issuers and no ART issuer. We cover this in euro stablecoins and MiCA and in the stablecoins Spanish banks are preparing.

The GENIUS Act in the U.S.

It is federal law (Public Law 119-27, signed on July 18, 2025), but as of October 16, 2026 it is not yet in effect: it applies on the earlier of 18 months after enactment or 120 days after final regulations (Sec. 20), and the Treasury expects January 18, 2027. From then on, only permitted issuers may issue payment stablecoins (Sec. 3(a)), with reserves of at least 1 to 1 in assets such as cash, deposits or Treasury bills, notes or bonds maturing in 93 days or less (Sec. 4(a)(1)), and without paying interest for holding them (Sec. 4(a)(11)). Details in GENIUS Act.

Risks

Loss of the peg if the reserve or collateral falls short, or if many holders redeem at once; issuer risk and the risk of the reserve custodian; smart contract failures; and differences between jurisdictions. Nor is it central bank money: an EMT white paper must warn that it is not covered by deposit guarantee schemes (Art. 51(4)), while the digital euro would be a direct liability of the ECB or the national central banks.

Uses

Cross-border payments and collections, settlement of tokenized assets, and treasury. Paying and getting paid with them means solving accounting integration, conversion and compliance: that is what we do in stablecoin payments. The regional regulatory map is in stablecoins in Latin America.

Frequently asked questions

Are stablecoins legal in Spain?

Yes. They are regulated by MiCA, an EU regulation directly applicable in Spain (Art. 149). To offer an EMT to the public or seek its admission to trading, the issuer must be authorized as a credit institution or an electronic money institution (Art. 48(1)); for an ART, it must be authorized or be a credit institution (Art. 16(1)). The obligations fall on issuers, offerors and service providers (Art. 2(1)): someone who only buys them needs no authorization. The Banco de España supervises EMT and ART issuers (Art. 251 of Law 6/2023) and, according to the CNMV, since July 1, 2026 only authorized crypto-asset service providers may operate in Spain.

Who can issue a stablecoin in the EU?

It depends on the type. An EMT may be offered to the public only by its issuer, authorized as a credit institution or an electronic money institution, or by another person with the issuer's written consent (Art. 48(1)). An ART, by its issuer, if it is a legal person established in the EU and authorized by its supervisor (Art. 21) or a credit institution (Art. 17), or by another person with the issuer's written consent (Art. 16(1)). As of October 16, 2026, ESMA's register lists EMT white papers from 25 issuers, including electronic money institutions and credit institutions, and no ART issuer.

How can you tell whether a stablecoin complies with MiCA?

By checking ESMA's interim register, which publishes each week what supervisors report to it, so a recent authorization may take time to appear. As of October 16, 2026, it includes, for example, the white papers of USDC and EURC, from Circle Internet Financial Europe SAS, and of EURCV and USDCV, from Société Générale-Forge; Tether, the issuer of USDT, is not among the EMT issuers. ESMA warns that no authority has reviewed or approved the white papers in its register.

How is a stablecoin different from the digital euro?

In who issues it and stands behind it. A stablecoin is issued by a private company and its value depends on its backing; an EMT white paper must warn that it is not covered by deposit guarantee schemes (Art. 51(4) of MiCA). The digital euro would be central bank money, a direct liability of the ECB or the national central banks (Art. 4(2) of proposal COM(2023) 369), and as of October 16, 2026 it is still a proposal: the European Parliament has not yet adopted its first-reading position.

Do stablecoins pay interest?

In the EU, not for holding them: MiCA bars EMT and ART issuers and crypto-asset service providers from granting interest, and treats as interest any remuneration or benefit related to how long they are held (Arts. 40 and 50). In the U.S., once the GENIUS Act takes effect, issuers may not pay interest or yield solely for holding, using or retaining a payment stablecoin (Sec. 4(a)(11)).

Official sources

• Regulation (EU) 2023/1114, MiCA (EUR-Lex)
• ESMA interim MiCA register
• Law 6/2023 on Securities Markets and Investment Services (BOE, in Spanish)
• CNMV: MiCA, the new crypto-asset rules (in Spanish)
• Public Law 119-27, GENIUS Act (govinfo)
• U.S. Treasury rule 2026-19966 (expected effective date)
• SEC complaint against Terraform Labs (Feb. 16, 2023)
• European Parliament, digital euro procedure 2023/0212(COD)

Framework verified as of October 16, 2026. At Unknown Gravity we integrate regulated stablecoins into payment systems and tokenization platforms. We do not issue stablecoins and we are not an investment adviser. Talk to us.