circle's x402 protocol hit 140m transactions in 9 months at $0.31 average size. that's 518k daily micropayments in the range where stripe loses money and visa's interchange model breaks. coinbase just bundled x402 into AgentPay as a co-equal rail next to stripe and visa. same week grayscale adds 6 AI agent tokens to their consideration list. circle doesn't need to monetize x402 directly. every transaction settles in USDC. entrench USDC as the agent economy's reserve currency, earn yield on the float backing ...