const ethMantissa = 1e18;
const blocksPerDay = 4 * 60 * 24;
const aToken = new web3.eth.Contract(sEthAbi, sEthAddress);
const supplyRatePerBlock = await aToken.methods.supplyRatePerBlock().call();
const borrowRatePerBlock = await aToken.methods.borrowRatePerBlock().call();
const supplyApy = (((Math.pow((supplyRatePerBlock / ethMantissa * blocksPerDay) + 1, daysPerYear))) - 1) * 100;
const borrowApy = (((Math.pow((borrowRatePerBlock / ethMantissa * blocksPerDay) + 1, daysPerYear))) - 1) * 100;
console.log(`Supply APY for ETH ${supplyApy} %`);
console.log(`Borrow APY for ETH ${borrowApy} %`);