In theory, after Binance launched the USDC financial product with an annualized rate of 12%, the demand would increase significantly. However, USDC has instead been driven down to 0.999, a decrease of 10 basis points, indicating that during this period, a large amount of USDC was converted to USDT. What is going on? Typically, Binance's U trading pairs have better liquidity than USDC, so exchanging for U usually means buying spot. What is it that they want to buy?