USDC Dominates AI Agent Payments As Circulating Supply Stays Above MiCA’s €5B Threshold For 12 Months

The stablecoin market is quietly evolving, as a new report indicates that Circle’s USDC leads on key metrics, underscoring its growing popularity. As stablecoins rapidly become the default settlement layer for AI agent transactions, USDC appears to lead the race, according to a new industry study published Friday.

Many crypto networks have embraced artificial intelligence, with their execution layers powering numerous AI agents to unlock microsecond payment settlement speeds via the X402 protocol.

USDC leads in AI agent payments

The new wave of crypto adoption isn’t traders; it’s AI agents settling payments with stablecoins, according to a report released on Friday. AI agents are beginning to pay for things in the crypto market. The new report shows that USDC is the most popular stablecoin that agents utilize to settle on-chain payments.

On-chain data from Token Terminal shows that USDC dominates AI agent payments on Base and other crypto networks over the past 30 days, as the study above notes. Agents commonly route transactions through Algorand, Solana, Polygon, Canton, and other networks as settlement chains while paying in USDC. While USDC leads the market, the data identified USDC, EURC, and WARS as other major stablecoins agents also use to execute transactions.

USDT’s market share slides as USDC closes the Gap

USDC’s dominance in AI agent payments comes as its circulating supply has stayed between $70 billion and $80 billion over the past 12 months, far above MiCA’s €5B threshold. This means new money (powered by USDC) has entered the crypto market in massive amounts, far exceeding the regulator’s limit.

While USDT remains the market leader in the stablecoin sector, and by a wide margin, fresh data from Sentora shows its grip is gradually weakening as USDC closes the gap in both customer numbers and usage metrics. According to Sentora data, USDT’s share of the stablecoin market has risen from 20% to 24% over the past 24 months, while USDT’s has dropped from 70% to 60%.

This means more customers are using USDC for cross-border payments. While newer alternatives like USDS are gaining traction, USDT and USDC remain the most relevant stablecoins for user payments, liquidity, and infrastructure decisions.