Circle's USDC Takes 56% of Euro Stablecoin Trading From Tether

USDC Passes USDT in Euro Trading

Circle's USD Coin (USDC) has overtaken Tether's USDT in stablecoin trading against the euro, a reshuffle that euro-pair market data shows gathering pace through 2026. The USDC stablecoin now carries 56% of the trading volume in euro pairs, a share that stood at just 10% in January 2024. This is a market-share shift rather than a USDC price event, since the token stays pegged to the dollar. The swing tracks the timing: it accelerated after major exchanges restricted USDT trading for customers in the European Economic Area under the Markets in Crypto-Assets Regulation (MiCA), the EU framework that requires issuers serving the bloc to obtain authorization and hold compliant reserves. Because European customers rely on euro pairs as their main on-ramp and off-ramp, converting euros into dollar-pegged tokens on the way in and out of crypto markets, the restrictions redirected that flow toward MiCA-compliant alternatives. Depth moved with it. In spot trading against the euro, USDC order books now run roughly 40% deeper than USDT's, and execution on size depends on that depth, the practical output of each venue's order book model. Deeper books mean smaller slippage on customer-sized orders, which compounds the share gain as flows concentrate in the compliant token. The lead is regional, not global, and it is measured in trading share and depth, not supply. Tether remains the larger issuer worldwide, with circulating supply about 2.5 times USDC's by market cap, so the euro result is a regulation-shaped exception rather than a global reversal. It is, though, the market regulators touched first, and the share data shows what that touch can do. The lesson of the past two years for issuers is plain: access to a fiat on-ramp is granted by rule, not won in the books.

The mechanics behind the swap run through the European Banking Authority. Two weeks ago, the EBA designated USDC as the EU's first “significant e-money token” under MiCA, a classification that places the stablecoin under the authority's direct supervision and binds Circle to additional regulatory requirements. MiCA reserves that label for tokens whose scale makes them systemically relevant to the bloc's payments system, which is why the designation carries extra reserve and oversight obligations rather than a new authorization. The designation is the enforcement end of the same regulation that pushed venues to restrict USDT, and it arrived just as Circle's euro order books took the depth lead. Circle has built out the rails that go with it: the company recently scrapped USDC and EURC redemption fees in excess amounts, lowering the cost of moving between its dollar and euro tokens, and it now pairs institutional mints and redemptions in hourly auctions. The US is running a version of the same script under the GENIUS Act, the US framework for payment stablecoins. On Oct. 21, the Office of the Comptroller of the Currency issued its first final rule under the law, establishing reserve and redemption requirements for stablecoin issuers under its supervision, effective Jan. 18, 2027. The reserve side covers what backs each token; the redemption side covers how holders cash out. This is a final rule, not a proposal, so issuers inside the OCC's perimeter have a fixed compliance date. A second gate follows in July 2028, when US platforms become restricted from offering stablecoins from issuers that do not meet the law's approval requirements. Circle has pursued authorization on both sides of the Atlantic. Tether has taken a different path, launching USAT, a separate US-focused stablecoin, while keeping USDT as its global product. The two issuers are betting differently on the same question: whether approval is a moat or a constraint.

EBA and OCC Hold the Keys

The euro data amounts to the first full test of what happens when a fiat on-ramp is gated by authorization, and the answer favors the compliant issuer. Once venues must drop non-approved tokens, trading share, depth and redemption economics follow the rulebook rather than incumbency. Europe has already run that test; the US schedule is written, with a Jan. 2027 reserve standard and a July 2028 platform restriction. Neither Circle nor Tether decides where the liquidity settles next. The EBA and the OCC do, and both have already put their dates in writing.