I created this simulator for my personal use to estimate Solend rewards after one year of mSOL Token - Solana (SOL) looping assuming rewards and interest rates do not change, which they almost certainly will. The claim was you could stake SOL using Marinade or jup.ag (whichever is best at the time) to receive mSOL which you lend on Solend. The loaned mSOL then becomes collateral for you to borrow more SOL for you to repeat the process. The idea is that the rewards from Solend and staking SOL will offset the interest on the loan. The APY for supplying mSOL is almost negligible, the quotes you get include rewards in other tokens and they change frequently without notice.
Disclaimer: The LUNA/UST crash really emphasized how altcoins just is not for me at this point in time, but I still think the idea of decentralized lending is intriguing and hope to better understand it. As I understand it, the value of SOL, Solend rewards and Solend interest rates will fluctuate without notice within a year and has already changed since you loaded this page. Please make sure you understand the risk associated with borrowing on Solend and crypto in general.