Visa on-chain data shows that USDC accounts for 70% of adjusted transaction volume, while USDT has fallen to 25%. In 2020, USDT accounted for nearly 90% and USDC less than 10%; in 2022, USDC rose to 45%; now the gap has completely reversed. Behind this is Wall Street's push: institutions such as Standard Chartered and Bank of New York Mellon have embedded USDC into settlement processes, while USDT has been marginalized due to compliance shortcomings. The adjusted transaction volume in the first half of the year was $8.82 trillion, exceeding the total for all of 2024, but lower than the $10.8 trillion projected for 2025 — overall growth is slowing, but the structural shift is irreversible. The risk is that USDC's institutionalization relies on Circle's single-point credit and regulatory endorsement; if there is a crack in reserve management or compliance, the entire stablecoin system will face a more concentrated systemic shock than during the USDT era.