USDC Leads AI Agent Payments; Supply Tops MiCA €5B for a Year

Circle’s USDC is the stablecoin most often used by AI agents to settle on-chain payments, according to a new industry report published Friday and covered by Zycrypto. The same study notes that USDC’s circulating supply has held between $70 billion and $80 billion over the past 12 months, far above the €5 billion threshold set under the EU’s MiCA rules, Zycrypto reported on October 18, 2026.

The report frames AI agents, not human traders, as the new source of crypto adoption: agents are increasingly paying for goods and services with stablecoins rather than holding volatile assets. On-chain data from Token Terminal cited in the study shows USDC leading those payments on Base and other networks over the past 30 days.

Key facts

• USDC is the most popular stablecoin for AI agent payments on Base and other networks over the past 30 days, per Token Terminal data cited in the report.
• USDC’s circulating supply has stayed between $70 billion and $80 billion over the past 12 months, well above MiCA’s €5 billion threshold.
• Agents commonly settle transactions through Algorand, Solana, Polygon and Canton, paying in USDC.
• Sentora data cited in the report shows USDT’s share of the stablecoin market falling from 70% to 60% over 24 months, while USDC’s rose from 20% to 24%.
• The report also identified EURC and WARS as stablecoins agents use to execute transactions.

AI agents as a settlement channel

The study describes a shift in why stablecoins are used. Earlier growth came largely from trading and liquidity provision; the report points to machine-driven payments as a newer demand source. Crypto networks have been building execution layers that let agents settle payments at microsecond speeds, with the X402 protocol named in the Zycrypto account as one such channel.

This matters for stablecoin issuers because agent payments generate recurring transaction flow rather than one-off trading volumes. USDC’s lead in that flow is a usage signal, not necessarily a revenue signal: the report does not disclose transaction values, only that USDC is the dominant asset by count of settlements on the networks tracked.

USDT stays ahead overall

Despite USDC’s gains, USDT remains the largest stablecoin by a wide margin, according to the Sentora data. The report’s own figures show USDT still holding 60% of the market against USDC’s 24%, even after a decade-low share for Tether’s token relative to its peak.

Zycrypto’s account also notes that newer alternatives such as USDS are gaining traction, though USDT and USDC remain the most relevant stablecoins for user payments, liquidity and infrastructure decisions. No figures for USDS’s share were provided in the report.

Why it matters

Stablecoin supply above the MiCA threshold is significant for issuers operating in the EU, where the rule sets a trigger point for additional regulatory obligations. USDC’s 12-month run above that level, at roughly 14 to 16 times the threshold, indicates the bridge asset has scale that regulators will scrutinise, not just a niche following.

For developers building agent-based payment products, the report’s findings suggest USDC is the default rail to integrate first, even as networks compete to host the settlement traffic.

What to watch

Token Terminal’s rolling 30-day data on agent payment volumes will show whether USDC holds its lead as more networks and issuer-backed tokens enter the market. Any EU update on how MiCA thresholds are enforced for stablecoin issuers would also bear directly on the supply figures cited here.

This article is not financial advice. Stablecoin and crypto markets are volatile and uncertain, and reported figures should be verified independently before making investment decisions.

Disclaimer: This article is for information only and is not investment, financial or trading advice. Cryptocurrency prices are highly volatile. Always do your own research.

Source: ZyCrypto