To minimize the friction of delegation and allow delegators to easily switch between validators, redelegation feature is supported in Harmony Staking. If a delegator wants to redelegate tokens from one validator to another, he or she can undelegate the tokens which will be locked immediately. After that, any new delegations will try to utilize the locked tokens first and, if not enough, the liquid tokens from the user's wallet. Note the locked tokens are only available for redelegation after the end of the epoch when they were first undelegated. This is to make sure the tokens can still be slashed within the same epoch of undelegation if they are used for malicious double signing.