By spreading the LUNA to several validators, delegators are more likely to avoid maximum slashing risks that sometimes occurs (validator slashing hurts both validator and delegator funds)

In terms of the top 25 delegators by LUNA staked, it's fair to say that the delegation is spread out across a few validators. However, there are some delegators who tend to delegate a huge chunk of their LUNA to a validator.

In terms of the top delegators, there are 2 address which has over 60mil LUNA delegated and the lowest being 1.9 mil LUNA.

Delegators play a crucial role on Terra because they determine which validators receive this designation and voting by delegating their Luna. Holders can choose up 130 different validators to delegate to and here are top 25 validators by total LUNA staked.

On Terra, LUNA holders delegate their LUNA to a validator in return fo staking rewards. This allows LUNA holders to delegate their LUNA instead of setting up a validator node.