sDAI is a lending market on Spark (Ethereum), listed as Savings Dai. Depositors supply sDAI to the market and earn a variable interest rate paid by borrowers, who post collateral and are liquidated if their loan outgrows the market's limits. The rate floats with utilization — how much of the supplied sDAI is borrowed at the time — so the market is used to earn on an idle sDAI balance, or to borrow against collateral without selling it.
