Validators have the capacity to distribute payouts to only 512 nominators for each era. When a validator receives nominations from more than 512 nominators, it becomes "oversubscribed." Rewards are only allocated to the top 512 nominators who have staked the highest amounts with an oversubscribed validator.

In simpler terms, if your active validator is oversubscribed and your stake ranks 513th or lower, you will not be eligible for staking rewards.

How to Identify if a Validator is Oversubscribed and Your Eligibility for Rewards

Within the Staking Dashboard, an oversubscribed validator is marked with a warning symbol and a red number.

This red figure represents the minimum bond necessary to qualify for rewards when nominating this particular validator. If you choose to nominate an oversubscribed validator and your stake exceeds this minimum threshold, you will earn staking rewards for supporting the validator. Conversely, if your stake falls below this amount, you will not receive staking rewards, although you may still be subject to slashing if the validator engages in misconduct.

If one of your nominated validators becomes oversubscribed, you might consider altering your nominations.