Compound is a DeFi lending protocol that allows users to earn interest on their cryptocurrencies by depositing them into one of several pools supported by the platform. When a user deposits tokens to a Compound pool they receive cTokens in return. These cTokens represent the individual’s stake in the pool and can be used to redeem the underlying cryptocurrency initially deposited into the pool at any time. For example by depositing ETH into a pool you will receive cETH in return. Over time the exchange rate of these cTokens to the underlying asset increases which means you can redeem them for more of the underlying asset than you initially put in — this is how the interest is distributed. On the flip side borrowers can take a secured loan from any Compound pool by depositing collateral. The maximum loan-to-value (LTV) ratio varies based on the collateral asset but currently ranges from 50 to 75%. The interest rate paid varies by borrowed asset and borrowers can face automatic liquidation if their collateral falls below a specific maintenance threshold.Since the launch of the Compound mainnet in September 2018 the platform has skyrocketed in popularity and recently passed more than $800 million in total locked value.