USDC

USDC is in the news for three developments that landed inside a week. On 27 October, Kaiko published data showing USDC now accounts for 56% of stablecoin trading against the euro, up from 10% in January 2024, with order books roughly 40% deeper than USDT's (Cointelegraph). The same day, Circle and ACI Worldwide announced a pilot that settles USDC on Colombia's Bre-B instant-payments network (ACI Worldwide). A shareholder suit on 22 October and a Mizuho downgrade on 26 October add the third. Underneath all three sits the same question: whether USDC keeps taking share from USDT, and what its issuer earns on the balances it holds.

Euro trading moved to the compliant coin

The shift is regulatory rather than a change of preference among European traders. Tether's USDT lost eligibility for regulated European order books when the MiCA transition period ended on 1 July 2026, leaving USDC as the main compliant dollar stablecoin on venues that serve EU users (Inside Crypto). Tether declined to seek MiCA authorization because the framework requires large issuers to hold at least 60% of reserves in European bank deposits, a mandate its own reserve mix does not meet: about 80% short-term US Treasury bills and roughly 5% cash (Inside Crypto). Circle holds an Electronic Money Institution license in France, which passports it across all 27 EU member states, and the European Banking Authority has designated USDC the first significant e-money token in the bloc (Inside Crypto). Tether's supply is still far larger: about $183 billion against $72 billion to $74 billion for USDC, roughly 2.5 to 1 in Tether's favour, and it keeps its dominance in offshore and emerging-market venues (Inside Crypto).

A settlement pilot on a central bank rail

Circle and ACI Worldwide are piloting USDC settlement inside existing banking infrastructure across Latin America, starting in Colombia. ACI built the central infrastructure behind Bre-B, the country's interoperable instant-payments system, and the pilot pairs USDC with ACI Connetic, the orchestration platform that brings traditional payment types, digital assets and card payments onto one cloud platform (ACI Worldwide). Bre-B recorded more than 500 million transactions in its first five months of operation, as of March 2026, and passed 100 million registered payment keys in the same stretch (CryptoBriefing). Circle's chief commercial officer Kash Razzaghi said the partnership gives institutions a practical path to see how USDC fits payment environments they already use (ACI Worldwide). The work extends Circle's regional push into dozens of emerging markets, on top of an earlier USDC foothold through Mercado Pago (Decrypt).

The reserve income behind it is contested

Two stories, on 22 and 26 October, put the same line of Circle's income under pressure. On 22 October, a Circle shareholder filed suit in the US District Court for the District of Columbia against Donald Trump, World Liberty Financial and US Special Envoy to the Middle East Steve Witkoff, alleging that a route for foreign governments to use the USD1 stablecoin left Circle unable to compete with USDC (Cointelegraph). The complaint estimates $70 million to $82 million in potential annual reserve income tied to business the plaintiff says USDC lost to USD1, and concerns a $500 million UAE-linked investment and a $2 billion stablecoin deal (CryptoSlate). The White House called the suit "frivolous" (Cointelegraph).

On 26 October, Mizuho cut its price target on Circle to $43 from $45 and kept an Underperform rating, writing that AI personal assistant engines pose a marked risk to Circle's medium-term revenue (The Block). Reserve revenue made up 95.2% of Circle's total revenue in the second quarter of 2026, and Mizuho estimates a 10% to 20% haircut to that line if agents steer holders toward higher-yielding fiat products (CryptoBriefing). The bank cut its 2027 forecast for average USDC in circulation to $101 billion from $108 billion, which lowers projected reserve revenue by 5% to $4.1 billion, and trimmed adjusted EBITDA by about 5% to $603 million (Blockonomi). Circle's shares closed down 7% at $79.84 on 26 October (The Block).

Against that, Circle's own figures show the scale of what is at stake. In a blog post on 16 October, the company said USDC settled more than $36 trillion in onchain transaction volume in the first half of 2026, that Circle minted and redeemed more than $315 billion of it, about $1.7 billion a day, and that by June USDC carried roughly 77% of global stablecoin transaction volume, up from 60% a year earlier (Circle).

What to watch

4 November 2026, when Circle reports third-quarter results, which should clarify USDC balances and yield data (CryptoBriefing). 18 July 2028, three years after the GENIUS Act became law, when it becomes unlawful for a digital asset service provider to offer or sell a payment stablecoin in the United States unless a permitted issuer issued it (GENIUS Act, section 3(b)). And whether banks in the Bre-B pilot move past testing, and whether Colombian regulators stay comfortable with stablecoin settlement touching a central bank network (CryptoBriefing).