USDC's euro share jumps to 56% on MiCA

USDC's share of euro stablecoin trading hit 56% in October, up from 10% in January 2024, according to a new Kaiko report. Tether's USDT held the top spot for years; now its order books are roughly 40% thinner than Circle's in euro pairs.

MiCA's mechanics

The reversal did not happen gradually. It tracked a regulatory trigger: the EU's Markets in Crypto-Assets Regulation gave exchanges a reason to restrict USDT for customers in the European Economic Area, and liquidity moved with the rule.

• USDC's euro trading share: 56% in October 2026, up from 10% in January 2024, per Kaiko.
• USDC order books now run about 40% deeper than USDT's in euro pairs, Kaiko found.
• Tether's global circulating supply is still roughly 2.5 times larger than USDC's.
• The European Banking Authority named USDC the EU's first "significant e-money token" under MiCA, placing it under direct EBA supervision.
• The OCC issued its first final rule under the GENIUS Act on Oct. 21, setting reserve and redemption standards effective Jan. 18, 2027.

What the euro number signals

The obvious read is that USDC won a popularity contest. The share numbers say something narrower: compliance access, not consumer preference, moved the market.

Tether is still the bigger stablecoin by a wide margin globally. It just got cut out of a specific lane where euro traders enter and exit crypto.

Kaiko calls stablecoin-to-euro pairs the main on-ramp and off-ramp for European customers. Lose share there and you lose the point where new money enters, even while total supply stays dominant elsewhere.

That's a structural edge, not a brand win. Exchanges restricted USDT access under MiCA; traders followed the liquidity that was still allowed, and deeper books built on themselves once the shift started.

The US parallel

Kaiko flags the GENIUS Act as the same mechanism, applied domestically. The OCC's Oct. 21 rule sets reserve and redemption terms for stablecoin issuers it supervises, with platform restrictions on non-approved issuers arriving in July 2028.

Circle has pursued authorization in both the EU and the US. Tether has instead launched USAT, a separate US-focused stablecoin, rather than bring USDT itself into the GENIUS framework.

If the EU pattern holds, the deciding factor in the US will not be reserve quality or redemption speed. It will be which issuer's paperwork clears first, and which coin exchanges are legally free to keep listing.

What would confirm this

• USDC's euro share holding above 50% through Q1 2027, past the initial MiCA shock, rather than reverting once traders adjust.
• Whether USAT gains meaningful US trading share once GENIUS Act platform restrictions start biting in July 2028.
• Tether's global supply trend relative to USDC: a narrowing of that 2.5x gap would show the EU effect spreading beyond euro pairs.