Stablecoin supply rotation is accelerating: USDC circulating supply dropped 8.2% QoQ while USDT maintained 61% dominance, signaling institutional preference shift toward yield-bearing alternatives and reserve transparency. On-chain data shows $2.3B net outflow from USDC to USDT and USDP across major chains in the last 30 days, a structural reallocation tied to Circle's reserve composition concerns.