The reserve’s interest-rate model showed an optimal utilization level of 94%. With almost all supplied $USDT already borrowed, large withdrawals leave less cash for other lenders to redeem and make borrowing more expensive. APR and APY are different measures: APY includes compounding.
Savings Vault Draws the Deposits
The destination was Spark’s $USDT savings vault, rather than a direct deposit into SparkLend. The 100 million $USDT deposit transaction minted spUSDT vault shares to the withdrawing wallet.
Spark Savings deploys assets through the Spark Liquidity Layer, with savings rates managed by Spark governance, according to its documentation. Its depositor yield is distinct from the rate borrowers pay in SparkLend.
Spark announced a 3.75% $USDT savings APY on Oct. 5, saying around $450 million was already deposited. Its $USDT savings dashboard showed $610.5 million in total value locked on Oct. 8 and the same 3.75% APY.
The wallet retained approximately 101.95 million aEthUSDT, Aave’s $USDT deposit token, according to its Etherscan holdings.