The total amount of CRV currently locked up is 618M CRV, with an average lock time period of 3.62 years. This amount of CRV is locked up in order to secure the Curve Finance Protocol and its users. The locked up CRV is used to secure the protocol from malicious actors, incentivize liquidity providers, and provide governance to the protocol. This locking of CRV has been done in order to ensure that the protocol is secure and well maintained, while also providing users with the ability to earn rewards for providing liquidity. By locking up this amount of CRV, Curve Finance is able to ensure that its users are protected and that its protocol is secure.