According to Cardano blockchain explorer Cexplorer, over 131 million ADA are currently delegated to retired staking pools, preventing 59,025 stakers from receiving staking rewards. Cexplorer noted that a total of 2,720 staking pools have been retired. When a staking pool is retired, delegators need to choose a new active staking pool to continue earning rewards, but their ADA assets themselves are not lost.